|
|
 |
Where am I now? Lawlink > Law Reform Commission > Publications > Appendix D - The Use of Computers for Keeping and Producing Records
Report 17 (1973) - Evidence (Business Records)
Appendix D - The Use of Computers for Keeping and Producing Records
CONTENTS
| Part | Paragraphs |
| 1. What is a Computer | 1-23 |
| 2. Programming-Operation | 24-31 |
| 3. Automatic Data Processing (A.D.P.) | 32-43 |
| 4. Accuracy of A.D.P. | 44-56 |
| 5. A.D.P.-Documentary Records | 57-63 |
| 6. A.D.P. in the Future | 64-69 |
| 7. Computers and the Lawyer | 70-72 |
| 8. Summary and Conclusions | 73-74 |
THE USE OF COMPUTERS FOR KEEPING AND PRODUCING RECORDS
PART I.-WHAT IS A COMPUTER?
1. A computer may be described as a device which is capable of accepting information, storing and processing it in accordance with a predefined sequence of instructions and supplying the results. 1 Processsing means performing mathematical operations, or comparing, sorting, analysing, editing, or consolidating items of data in accordance with mathematical or logical rules. In business applications the sequence of operations ordinarily is-
(1) information is put into the computer;
(2) it is stored and/or processed; and
(3) the stored or processed information is retrieved or put out in a legible form, generally as a print-out.
In technical applications the output may be used to control machines, engines, instruments and so forth.
2. There are two basic types of computers-analog and digital. Analog computers are used mainly for scientific and technical purposes. They operate on the principle of creating a physical analogy of the problem to be solved. Variables in the data are represented by the magnitude of physical phenomena such as voltage or current or length. The result of the calculation is obtained by measurement.
3. In business and commercial applications digital computers are used. Digital computers operate by taking advantage of the binary system of numbers. This system uses a base of 2 rather than the base of 10 which is used in the decimal system. There are only two digits, 0 (called zero) and 1. 2 In a computer these two digits are represented by such means as a switch being on or off, or a spot on a tape or disc being magnetized or not magnetized. Numbers and letters are represented in a binary or binary coded form, as a series of zeros and ones. Numerical and alphabetical data or information is stored and handled in the com-puter in this form. A similar principle is used in Morse Code in which letters and numbers are represented by combinations of dots and dashes.
4. Digital computers are classified into general purpose and special purpose computers. Special purpose computers are dedicated to one task for which they may be specially designed. General purpose computers perform a multitude of tasks. The computers used in most commercial undertakings are of this type. A typical general purpose computer consists of elements known as inPut devices, a central processor, external or peripheral storage devices and output devices.
Input Devices
5. Two input devices in common use are nunchcd card or punched paper tape readers. Information contained in plain lancuage documents (e.g., invoices), referred to as “source documents”, is transferred to cards or paper tape on which it is recorded by holes punched by a. machine having a keyboard like that of a typewriter. The cards or tape are passed through a sensing device which reads the information to the computer where it is stored. Input by these methods is comparatively slow, for example one card reader in current use reads 800 cards a minute each containing up to 50 or 60 characters.
6. Information which is printed in magnetic ink usin- a special script may be read direct into a computer by the use of an M.I.C.R. (magnetic ink character recognition) device. This method is used by banks to process cheques and deposits. There are also optical character recognition devices by which information in the form of distinctive marks (e.g., crosses on a census return) or printed in a special script or font may be read into a computer.
7. There are a number of devices having typewriter type keyboards which transmit information direct into the computer. These are referred to as “terminals” and are described as “on line”, a term which describes the operation of peripheral equipment under the control of the central processor. The simplest of these terminals is like a teleprinter. The information may be typed out on paper by using the keys. It may then be checked by reading it and its transmission into the computer completed by pressing a further key. Such terminals can generally be actuated by the computer to type information which it is putting out.
8. Visual display terminals use a similar keyboard in association with a cathode ray tube screen like a television screen. When the information is typed it appears in printed fonn on the screen and may be read to check that it is correct. It is thentransmitted to the computer by pressing a further key. Such terminals are of ten constructed for use to display information put out by the computer. Some terminals have facilities for producing very quickly a photographic type copy of the information displayed on the screen.
9. There are also terminals which enable the input and output of information in the form of maps, plans, diagrams and graphs. Other input devices will be mentioned later.
Central Processor
10. The central processor comprises the computer’s memory, the control unit and the arithmetical and logical unit. Its operation is controlled by a control program wholly or partially resident in part of the central processor’s memory. The control program is monitored and directed from a console. This is a teleprinter type terminal from which operating instructions may be sent (first being typed out by the operator) to. the control program of the central processor and by means of which this program types out reports on the progress of the particular procedure and on any operating errors which have occurred. Such instructions and reports are recorded on a continuous sheet of paper on which the operator also types particulars of the procedure being carried out. This record is known as the computer log. It is generally made in duplicate, the original being retained and the copy supplied to the person for whom a particular program has been run, if this is appropriate.
11. The memory is also referred to as internal storage. It is used to store the application program (generally called “the program”) 3 and also the information or data while the latter is being processed. The most common storage device consists of a large number of small ferrite rings or cores interconnected by wires. The cores may be magnetized in one direction to represent 0 and in the other to represent 1. Pulses of electric current are passed alone, the wires to create the appropriate magnetization or to read what it is. Each core represents one “bit” (i.e., binary digit) of information. To increase the processing capacity of a computer it is necessary to increase the storage capacity or efficiency of its memory.
12. The arithmetical and logical unit consists of the components and circuitry by which the arithmetic and logical operations necessary for processing are performed.
13. The control unit is a device for causing the computer to perform the desired operations in the correct sequence. Its operation is directed by the program. The program is a series of instructions which are recorded on magnetic tape or disc. The instructions are in effect signals which actuate the computer’s components and circuitry. Before processing begins the program is read from the tape or disc into, the computer’s memory, where it is stored during processing.
External Storage
14. External or peripheral storage is storage which is physically external to the central processor. Information is transferred to external storage from the central processor and may be read back to it when required. The devices commonly used for external storage are reels of magnetic tape, magnetic discs and magnetic drums. Information is recorded on these in a magnetic form. Each device is used with equipment which can “write” information on to it or “read” it off, such as a tape drive or a disc pack drive. Each device is capable of storing information for an apparently unlimited time.
15. Magnetic tape is the cheapest form of external storage. Information is recorded serially, that is one item after another, along the length of the tape. A standard reel of tape can hold about 20 million characters, that is, the contents of about ten paper-back novels. Magnetic tape is suitable for the periodic processing of large numbers of items in the order in which they are recorded on the tape.
16. It takes from 4 to 8 minutes, depending on the speed of the tape drive, to read the whole of a magnetic tape. Where it is desired to process items of information in a random order, or to. retrieve quickly such items for display or printing out by a terminal, magnetic discs or drums are ordinarily used. Reading heads are able to search for and retrieve any desired item of information from storage in such a device within a small fraction of a second. Discs and drums may also be used for processing where the number of items involved is reasonably low.
17. Maonetic tapes and some discs are portable and may readily be stored away from their associated equipment. Fixed discs and drums are sizable installations and are not readily moved. An external storage device may be used with any compatible computer.
18. The storage devices mentioned vary considerably in expense, storage capacity, the average time required to obtain access to a particular item of information and the rate at which information may be transferred to or from the device. Choice of the method of external storage depends upon circumstances and the nature of the desired processing.
Output Devices
19. Output devices are used for putting out information which has been stored or processed by the computer. A common device is the machine printer. This prints out information from the computer in plain language at rate of from 450 to 2,000 lines each of up to 132 characters per minute. The computer may be programmed to print out using any desired layout. This enables preprinted stationery to be used, the printer filling in the appropriate blank spaces. Printing is on continuous paper perforated so as to be readily split into sheets of the required size. Thus cheques, invoices, statements, stock sheets and the like may be printed out.
20. Teleprinter type terminals and visual display terminals have already been mentioned. Microfilm output devices are available which print out microfilm at a rate of 30,000 characters per second. Other devices enable information to be put out in the form of punched cards or punched paper tape for use in business machines or further computer processing. Voice output is available but is usually limited to answers to enquiries such as for credit bureau information or stock exchange quotations.
Comparative Operating Speed of Elements
21. Each element of the computer has a different operating speed. Input and output devices are the slowest. The arithmetic and logical unit is the fastest. Accordingly, in some installations small computers are used for the input of information which is recorded in external storage. A larger and more expensive computer is used for processing, the results of which are transferred to external storage. A small computer is then used to print out the information. This enables the large computer to be as continuously engaged as possible in its most economic use, that is processing.
22. Other installations achieve maximum use of the arithmetic and logical unit by simultaneously accepting input from a number of terminals, processing a number of programs and operating a number of output devices.
Location of Elements
23. Input and output terminals need not be adjacent to the central processor of a computer. Each element may be, and often is, located hundreds or thousands of miles away from the other. They may be connected by the telephone system, or by coaxial cable, or indeed by microwave radio transmission between earth stations or via a satellite.
PART 2.-PROGRAMMING-OPERATION
24. As mentioned processing is controlled by a “program”. 4 A program is a sequence. of instructions to be executed by the, computer to solve a given problem or carry out a desired procedure. Each program requires the computer to take an enormous number of steps. Early in the development of computers, writing a program was a tedious and lengthy task because the programmer had to prescribe virtually every step using a complicated coded language which would be “understood” by the particular type of computer. Such a language is called “machine language”. Each type of computer has its own machine language.
25. More recently, programming languages have been developed such as Cobol (Common Business Oriented Language) used for administrative or business applications and Fortran (Formula Translation) used for scientific and technical purposes. Cobol has a vocabulary of ordinary words and punctuation, the use of which has a defined meaning. Fortran uses standard technical expressions. These languages permit the user to state his problem or requirements relatively easily and simply. They are called “high level” languages. A program written in such a language is put in to the computer, generally using punched cards, and is processed using a special program which comes with the computer, known as an “assembly” or “compiler” program. This translates the program language used into the particular computer’s machine language. The program in machine language form is generally recorded on a tape or disc which may be stored for use when required. Cobol and Fortran may be used for programming a sizable number of different makes of computers. Some special purpose computers have their own programming language.
26. A program designed for a particular job is called an application program. The task of preparing an application program is sometimes facilitated by a collection of commonly required utility programs and subroutines (called a “program library”), any one or more of which may be incorporated in the application program. The program library is accommodated in external storage,and the bulk of it may be supplied by the computer manufacturer. There is stored in the computer a supervisory or control program 5 which is concerned with organizing the flow of work, dealino, with input and output and, among other things, controlling the movements of all the other programs. The term “software” is used to describe compiler programs, supervisory programs and the program library as opposed to “hardware” which refers to the mechanical, electronic, magnetic, and electrical components of a computer system.
27. Originally programming by the user was costly and required high level skill. Now any intelligent young person without special qualifications can be taught to write programs in Cobol or other high level computer language in a matter of months. Some simplified programming languages are available which enable a non-programmer to use a restricted set of programming instructions after a few days.
28. A program is basically a recorded series of signals designed to operate the computer as required for the particular processing. In addition to the program, a set of written instructions is prepared to be followed by the computer operator. This lists the steps to be followed to carry out the procedure in question -and specifies details such as the identification number of the program tape or disc to be used and of any tapes or discs containing information to be processed, what drive units the tapes or discs are to be loaded on to, what stationery is to be used for printing out, the various steps which will be carried out by the program, and what to do when instructions -are, printed out by the program. There are many,checks usually included in the program and the operating instructions to ensure that the correct procedure is followed by the operator.
29. A simple processing run might proceed as follows. The operator puts the program tape on the designated tape drive and instructs the computer to store,the program in memory by typing an instruction on the console and transmitting it to the central processor. When this operation is complete a message to this effect will be typed out on the console. He then, having loaded punchcards into the reader and put a tape on a designated drive, actuates the computer to operate the program to read the cards on to the tape. This brings into operation the edit part of the program mentioned in paragraph 47. During this process, the program may print out messages querying the validity of data on the cards. These error reports will be sent to the persons responsible for the data for checking purposes. When reading in is complete, the program prints out a message to this effect on the console. It may also print out data for checking purposes. If say the punchcards represent financial data, it will print out various totals specified by the program which may be compared with totals prepared when the data were in documentary form. If these do not agree the error may be located before processing continues or it may be left until after processing is completed.
30. Having read his instructions, the operator then loads the tape recording the data on to another drive, loads a second tape on to the appropriate drive, and instructs the central processor to commence the second part of the procedure, to sort the information on to the second tape in the order specified by the programme. The processing proceeds in this way, step by step, until finally the processed information is printed out on the machine printer.
31. It is important to appreciate that the computer cannot originate anything. It can do no more than operate on the material with which it is supplied in accordance with the instructions contained in the program. Consequently the program must contain instructions which enable the computer to produce a correct result no matter what combination of facts are presented to it for processing or in the course of processing.
PART 3.-AUTOMATIC DATA PROCESSING
32. The ordinary business use of digital computers is known as automatic data processing (A.D.P. for short) or, alternatively, electronic data processing (E.D.P.). This is ordinarily regarded as being divided into commercial type and mathematical type applications. Commercial type applications are divided into, accounting and non-accounting applications,, but sometimes, of course, both types are involved. A.D.P. is best explained by examples.
33. Commercial applications generally involve the acceptance of information, sorting it into an appropriate order, recording it, keeping it up to date, and makinc, it available as occasion requires. The procedure adopted is to establish a “master file” of the information. This consists of one or more tapes or discs or other external storage devices in which the basic information is recorded after editing 6 and sorting to a convenient order. This is then updated as required. If tapes are used, updatinc, is performed at regular intervals when a convenient amount of new information has been collected. The new information is ed-ited and sorted in the same order on to a tape. This and the master file are processed tocether to produce a new master file containing the updated information. The whole or parts of the current master file are printed out as required. If discs are used, it is possible to update the master file immediately new information is available, and to retrieve particular items of information at the time they are required by the use of a teleprinter or visual display type terminal. The reference number of the item required and the appropriate request code is transmitted to the computer and it prints out or displays at the terminal the information recorded.
34. A simple example of a non-accounting commercial type application is provided by the District Court Weekly Index. The minute sheets on which the entry of actions is recorded is typed on typewriters, which produce punched paper tape as an automatic by-product of the manual typing operation. The entries on the minute sheets are typed roughly in the order in which the documents commencing actions are filed and numbered. The paper tape thus contains in code form in approximate numerical order the number and the names of the parties to all actions commenced. At regular intervals the paper tapes are taken to the New South Wales Treasury A.D.P. Bureau. Using the computer’s paper tape reader, the information is transferred to magnetic tape. The reel of magnetic tape then comprises a file of the information in approximate numerical order. The computer is used to sort this information into alphabetical order of defendants. The sorted information is recorded on another magnetic tape which is the master file. The contents of the master file are then printed out providing an alphabetical index of cases. From time to time this index is brought up-to-date. The information relating to additional cases is similarly recorded in alphabetical order on maunetic tape. The master file and this tape are then processed together to produce a new master file containing an up-to-date complete index and this is printed out. The production of this index by computer shows an economic advantage over the previous manual system of index cards. It also provides an index at intervals and in a form which it would not be practicable to make by manual methods.
35. An example of an accounting application is provided by the Bank of New South Wales computer system. A brief outline is as follows. 7 The system uses magnetic ink character recognition (M.I.C.R.). Cheques and deposit slips have printed on them in magnetic ink the code number of the branch and the customer’s account number. As customers’ deposit slips and other documents such as cheques are received at the Bank’s E.D.P. Centre, the documents are proved and balanced on accounting machines which automatically generate control totals to which the computer must balance. As a by-product of this accounting function, the written amount of the cheque or the deposit slip and the amount of the control totals are simultaneously printed out on the appropriate documents in magnetic ink. These documents are then run through an M.I.C.R. reading machine and the information on them recorded on magnetic tape on which it is necessarily in random order. This process goes on continuously during the day. At the end of the day the transactions recorded on magnetic tape are sorted by the computer in branch number order, in account number order within the branch, and if related to a cheque, in serial number order. The sorted information is recorded on other tapes. This file of sorted incoming transactions is then checked by the computer against a master file of stop payment information and the computer prints out details of any cheques affected. 8 The transaction file is then processed against the master ledoer information file. This already contains, in the same order, all the information which is shown on a customer’s statement, complete up to that time. It is, in substance, a complete ledge account key on magnetic tape. This processing run, simultaneously with posting the ledger file with the day’s transactions, prints out day sheets for each branch, listing by account numbers the day’s transactions for each account and stating the balance of each account whether it has had any transactions or not. A reference is also given to the data on which each account was last operated. At the appropriate intervals, the master ledger information file is used to print out customers’ statements. Copy statements and the day sheets are kept at the branches. Thus each branch has an historical record of its customers’ dealings in the copy statements and the day sheets relating to the period since the close of the last statement. In essence the system is one in which the computer continuously generates documentary accounting records incorporating the results of the bookkeeping or acounting procedures which it has carried out.
36. Throughout the procedure, the program makes a large number of audit-type checks on the information the computer is processing. References are provided to each item of information so that when errors are detected the entries relating to the transaction can be traced back. This is called providing an “audit trail”. External balance work is also carried out at various intervals during the processing cycle.
37. In addition, a total of some thirty-five types, of reports are printed out during processing. Some twenty of these are printed out daily, the others periodically as required. These reports provide each branch with such information as account balances, overdrawn accounts, changes made to a customer information, unpo-sted transactions, and a great deal of other detail to keep the branch fully informed and to assist in the conduel of its dafly aff airs.
38. The Sydney Stock Exchange provides another accounting example. 9 The information on every sale note made between operators on the trading floor is recorded on punched cards which are then read into the computer and stored in random order on magnetic tape. At various times during the day this information is sorted and processed to enable several lists to be printed out. One of these is a list, in categories of shares and in alphabetical order of companies of all transactions. Another is a list of all transactions, broker by broker. Each broker’s section of this list is sent to him and forms his daybook. This list is again in alphabetical order of shares and shows the numbers and price of each parcel sold and whether the broker is buyer or seller for each transaction. Brokers who subscribe to the additional computer document service can complete punched transaction cards supplied to them from the computer which, when processed, result in the computer printing out their contract notes and share transfer forms for transmission to their clients.
39. The A.M.P. Society, the Government Insurance Office and other insurance companies make extensive use of A.D.P. Full details of all policies are recorded on magnetic tape or disc. These records are regularly updated by the addition of information relating to the payment of premiums, the making of claims, alteration of the terms of policies such as endorsements, expiry or renewal, or the issue of new policies. At appropriate intervals the computer is used to print out premium renewal notices and the like and accounts for the pavment of interest due on loans secured by policies. The A.M.P. has an immediate access installation. Full details of all its more than 650,000 life policies in New South Wales are contained in the storaae available in a cylindrical file of magnetic sheets called a “data cell drive”. The details required relating to anv policy can be displayed on any one of the society’s visual display terminals within a fraction of a second of the request being transmitted to the computer. Within a further minute a photographic print of this information can be produced by the terminal.
40. So far reference has been made to computers operated by the organization which furnishes the information and makes use of the results. Much data processing is, however, performed by various organizations for a number of subscribers or customers. Thus the New South Wales Treasury A.D.P. Bureau does the processing for most government departments. Commercial organizations engage in the processing of particular programs for individual customers. Such an organization is called a “utility” or a “bureau”. The customer may send his source documents to the utility which transfers the information to punched cards or be may produce his own punched cards or paper tape. These are read into the computer and, using the program written for the particular customer, or one of its own programs appropriate to the task, the utility has its computer print out the required records such as stock sheets, salary cheques. or statements of account. Such programs may be run serially, that is one after the other, this being known as “batch processing”.
41. Other organizations offer “time-sharing” facilities. In this kind of application, customers have their own input/output terminals at their premises by means of which information may be fed into the computer at the bureau, the appropriate program selected, and the output after processing received back. These terminals may be of the teleprinter or visual display type or the customer may, in some instances, have input devices such as card or tape reading units and output printing machines. One time-sharing facility used by many subscribers in Sydney is the Honeywell G.E. facility, the computer of which is located in Melbourne.
42. It is already not uncommon for a computer in one State to be linked by telephone line to terminals or a computer in another State and for input data and output to be transmitted from one State to the other. Such usage of computers is likely to increase. The Postmaster General’s Department is now installing special cables to provide high speed computer links between Canberra, Sydney and Melbourne. It is likely that, in some years from now, banking clearances will be made by the use of an interstate computer network. Clearance information may be transmitted from one State to a computer in another and the output be printed out in a third. Further, regular data processing involving the use of or co-operation with computers in other countries linked by telex or satellite communication may be not far off.
43. There are, of course, regular computer-users who are not concerned with the storage, processing or retrieval of information, but use general purpose digital computers for the purpose of calculations. For instance, the Lands Department now does much of its mapping from aerial survey. The dimensions on the photographs are corrected by information derived by ground survey of control points. This correction involves lengthy, complicated and tedious calculations. These calculations are regularly performed by computer, the output being on punched cards which are used to actuate automatic mapping or map drawing machines. The computer processes in 20 minutes calculations which previously took 3 months using mechanical calculating machines.
PART 4.-ACCURACY OF AUTOMATIC DATA PROCESSING
44. There can be no doubt that records may be kept by computer to a greater standard of accuracy than is possible by other means. On the other hand there are occasionally accounts in newspapers of errors, sometimes of a capricious and absurd kind, which are said to have been committed by a computer. What are the factors on which the accuracy of computer processing of information depend?
45. The first and basic factor is, of course, the accuracy of the source documents. Apart from errors detected by the edit program referred to in paragraph 47, the reliability of the output from the computer can be no greater than that of the input. As computer men say, “garbage in equals carbage out”. For this reason, the hearsay exception which we recommend is subject to conditions which ensure that any statement produced by a computer which would be rendered admissible as evidence is baseli on reliable information. 10
46. Secondly, the information in the source documents must be accurately put into the computer. There are a great variety of means by which this process is verified. If punched cards are used they are first punched by an operator usine a typewriter type machine who reads the source document. Another operator then repeats the process using a verifying machine which signals if the punching differs, and if it does not, punches a verification mark in the card. Under this system a card does not go forward unless both operators make the same error or the second operator fails to do her job. Similar methods may be used to verify punched paper tape or reliance may be placed on a visual check of a plain languace document produced simultaneously. If information is transferred direct from the source document into the computer using a typewriter type on-line terminal, the check used may be a visual comparison of a typed copy produced simultaneously or of a copy showing on the cathode ray tube screen of the terminal. Or the information may be transmitted twice and only accepted by the computer if the second transmission completely matches the first. There are other means employed to put information into a computer althouah those just mentioned are at present the most common. Whatever means are adopted, both the user and the supplier of the equipment are naturally concerned to avoid inaccuracy and various methods are used to do this.
47. The computer program ordinarily includes a number of checks both on the accuracy of the information in the source documents and on the accuracy of its transfer to the computer. Generally the information in source documents can be expected to be within predetermined limits. The computer can be programmed to reject any information outside these limits. For instance, if mortgage payments to a building society are being recorded, any payment outside the ordinary limits of the instalments can be rejected when the card for that payment is read in, and the computer will print out an error report to enable the payment to be checked. If it is wrong it may be corrected. If right, it can then be read into the computer. In most situations many such checks can be devised and errors in the source documents detected which might not be found at such an early stage by manual processing, This often includes corresponding checks but they are not always made. This part of the proaram is called the “edit program”. A great deal of attention is generally paid to it and the checks involved are often very ingenious. For instance, where items are given reference numbers an extra digit, called a “check digit”, is often added to the number in the source document. This is derived by applying a formula to the reference number. When the reference number with the added digit is read into the computer, the computer calculates for itself what the check digit should be and rejects the information, printing out an error report, if it is not the same as that read in. Checks of the kind mentioned not only validate the accuracy of the information in the source document but also ensure that it has been accurately read into the computer.
48. Thirdly, the same kind of checks are constantly made during processing. These checks further validate the source information, the accuracy of its transfer from one part of the computer to another, and the accuracy of any mathematical or logical procedures involved in the processing. They include various kinds of balancing procedures made possible by the logic of the processing. For instance, as non-numerical information is recorded in a numerically coded form, the accuracy of its transfer from one part of the computer to another may be checked by balancing its numerical sum in one part against that in another. Generally two-thirds of an A.D.P. program is devoted to the edit program and to checks and verifying procedures of this kind.
49. What is called a “parity check” also guards against loss or distortion of information in transit. Information, whether alphabetical or numerical, is recorded in the form of binary digits, that is 0’s and 1’s, in blocks of magnetic representations. Extra digits called “parity bits” are added automatically to each lateral and longitudinal row of representations so that, for instance, there is always an even number of l’s in every row. The computer rejects any item in which the requisite parity is absent. It then may print out an error report. In some systems the looic of the check enables the error to be corrected automatically. The technique is called adding “redundancy” to each representation. It may be applied so as to achieve a greater or less standard of error detection as circumstances are thought to require.
50. Generally speaking it may be said that with a well-prepared program the possibility of undetected error being caused by technical defects in the processing of information is very remote indeed. Apart from this, the reliability of the components now used in the electronic circuitry of computers and modern techniques of regular preventive maintenance make technical error a rare occurrence. Further, failure of a component automatically stops processing. It is not allowed to continue exposed to error resulting from the failure.
51. Fourthly, the adequacy of the program is an important factor. Errors of the dramatic kind mentioned in paragraph 44 are caused by deficiencies in the program. Such deficiencies must be attributed to human failure, not machine failure. They arise from two sources. The first step in the application of A.D.P. to any system of record keeping is to analyse the data system concerned to find out what is involved in terms of the logic employed by the computer, what are the possibilities which must be provided for and to set up a system which can be maintained by A.D.P. Errors may creep. in at this stage if all possible combinations of circumstances are not provided for or if the analysis is incomplete.
52. The next step is to write an application program which is appropriate to the system set up. Here errors may creep in, particularly in the failure to provide for all possibilities or in omitting some necessary step in the procedure. It is said that very few programs are free from error on the first attempt.
53. However, it is usual to subject pro ms to rigorous and exhaustive testing of various kinds before th are relied upon in processing. When these tests have been completed, the previous system is normally continued for a substantial period after computer processing is begun so that the results of the A.D.P. may be checked against it. Sometimes, however, an error in a program may go undetected for years, until the unusual combination of circumstances not provided for occurs. Inadequate system analysis or hurried programming undoubtedly lead to error in many cases. In general such errors are detected at an early stage but often an accurate system is not established for a substantial period.
54. Finally there is the question of error at the output stage. Line-printers or teleprinter type terminals are, of course, subject to mechanical breakdown. A line-printer may omit a letter or a figure but it will be rare for the mistake not to be obvious to the reader. A teleprinter type terminal may omit a character or print a wrong character. Here again the mistake will rarely not be obvious. It is routine to test printers and teleprinter type terminals every few hours during operation by the use of a test program to ensure that every letter, figure and punctuation mark is being printed or typed correctly. A visual display screen type terminal might because of some malfunction, not display complete letters or figures. Once again the error will be obvious.
55. Generally on the question of accuracy of A.D.P. in relation to record-keeping, it must be remembered that as the whole purpose of any such application is to provide documents and records which are accurate so that they may be used in business, or business decisions taken in reliance upon the information contained in them, a system known to be unreliable is unlikely to be retained.
56. The general conclusion to be drawn is that, where a computer system has been properly established and is properly controlled, the information in documents printed out or displayed on a screen in A.D.P. for business or similar purdoses which is apparently regular and sensible should be as accurate as the information put into the computer from which it is derived.
PART 5.-A.D.P.-DOCUMENTARY RECORDS
57. In most traditional methods of record-keeping, the passage of information through the system is documented and the documents are arranged in an order which facilitates searching for a particular document. A simple example is purchase of an item out of petty cash recorded first by a voucher, entered in a cash book and then as a part of a total carried to a ledger account. The vouchers would normally be kept in the order in which they are entered. This is not necessarily the case if A.D.P. is employed.
58. Because of the sorting capacity of computers, it is not necessary that the source documents be in any particular order. A file containing, say, 75,000 items each comprising approximately 100 characters can be sorted from completely random order into any predetermined sequence in one hour or less. The source documents may be first recorded in random order on tape or disc but, as there is generally no point in printing out the information at this stage, no document is produced which indicates the order in which the source documents may be stored, In the Stock Exchance application 11 the sale notes are stored in completely random order on a day to day basis. Consequently it may sometimes be impractical to search out source documents. In a particular case, this may affect the weight to be attached by a court to a statement in a document produced by a computer, but it is not a consideration relevant to admissibility.
59. Printing out of information is expensive and generates large volumes of paper. In the early days of A.D.P. computer users were prone to have the information stored printed out in full frequently, to provide visual evidence that the system was in fact working. There is a growinc, tendency to be selective as to what information should be printed out and how often. Thus, for instance, if stock is recorded by A.D.P., instead of printing out a list of the entire stock at intervals, the computer might be programmed to print out only a list of items the number of which has fallen below a predetermined level. Consequently, there may be cases where information is stored by a computer in which no print-out has been made in the course of business containing a statement of a fact recorded by the computer of which it is desired to give evidence. There should be provision that a print-out made solely for the purpose of proceedings should be admissible. 12
60. Another consequence of selective printing out is that there may not be a documentary record of the progress of particular items through the system of record-keeping. In many accounting applications steps are taken to record an “audit trail” and this enables items to be followed throuah the system for checking purposes. In some accounting applications records are kept in an historical form and print-outs made which provide a complete and self-contained documentary set of accounting records. An example is the banking application described above. 13 Inability in a particular case to trace a statement in a docu ment produced by a computer through the system of record-keeping to the source documents may affect the weight to be attached by a court to the statement but should not affect its admissibility.
61. In some cases, for reasons of business convenience, some documents may not be retained for any length of time, for example, where the object of the application is the production of statistics. Again in the law this may affect weight but should not affect admissibility.
62. In applications which involve the recording of information and its updating from time to time, steps are ordinarily taken to preserve a record of recent changes. For instance, if the processing is done on tape, it is usual to retain the three previous master tapes and their corresponding transaction tapes. The current tape is known as the son tape and the three previous tapes as the father, grandfather and great grandfather tapes. There is always an available record of the previous three generations of chance in the information on the son tape even if printing out has been incomplete. If the processing has been on disc there may not be such a record. For mechanical reasons, an individual item on a tape cannot be erased by recording over it, but on disc this may be done. Information recorded on discs is often updated by recording the new information in the same physical place on the disc thus erasing the old. This is known as “destructive updating”. The new information is often simultaneously recorded on tape and filed thus providing a record of change referred to as “tape back up”. In other cases no such record of change is kept but periodically the contents of a disc are transferred to tape, the term used is “dumped”, which is then filed. In cases of the latter kind it may be difficult to establish the immediate past history of an item of information except by recourse to the source documents. The matters mentioned in this paragraph may on occasions be relevant to the weight to be attached by a court to a statement, but not to its admissibility.
63. In traditional systems of record-keeping it is usual to, keep copies of documents sent to other parties, for example, statements of account, invoices, and insurance policy renewal notices. If these are produced by A.D.P. they can be printed out in duplicate but often there is no business reason for doing so. Proof of the contents of such a document may depend on the tender of a print-out of the information in question made for the purpose of the case, and on evidence that on a particular day the program which would have resulted in such a document being printed out was run, and on evidence of the system pursuant to which the documents printed were then posted. Under our proposal, the computer log should be admissible evidence of some of these matters 14 and a print-out made for the purpose of the case should be admissible. 15
PART 6.-A.D.P. IN THE FUTURE
64. A number of areas of change are indicated by present developments. In-put of information is now one of the slowest and most expensive aspects of A.D.P. Dramatic changes are inevitable. It seems that transfer of information to punched cards or paper tape, as a first step to reading it into, the computer, will give way either to direct entry from the source document to the computer by the use of a keyboard terminal, or to transfer by means of a keyboard terminal to magnetic tape in a cassette from which the information may be read into the computer at a much higher speed than from punched cards or tape. Systems can be envisaged in which there will be no source documents, information being entered direct to magnetic tape, the evidence of entry being the next printout.
65. What is called “remote batch processing” seems likely to increase. The customer has his own terminal with multikeyboard input, a videoscreen for checkina and a printer. Information to be processed is recorded by the customer on cassette tape using his own input equipment. When the customer’s turn to use the utility’s computer has arrived, the information is read into it from the cassette over the telephone line, processed, and returned to the terminal where it is recorded again on cassette tape. This is run through by the customer and operates the terminal’s printer to print out the results of the processing. Such a terminal may include its own “minicomputer”.
66. Smaller and cheaper computers are becoming available. Also there is a growing supply of good secondhand computers. These factors may mean that many relatively small organizations will acquire their own computers. An increasing supply of cheap computers and the growth of remote batch processing may cause an enormous increase in the use of A.D.P. during the next decade.
67. Another likely change is the increasing use of computers linked to each other althouah considerable distances apart. B.O.A.C. has a worldwide computer network, said to have cost £42 million, which not only processes all seat bookings but handles accounting, statistics, stock control, maintenance schedules and, among many other tasks, calculates the most economical flight paths having regard to weather conditions and other factors. Four computers, in London, New York, Sydney and Hong Kong are linked to the central computer in England which is called “BOADICEA”. As previously mentioned, it is possible that some time in the future clearing operations for banking in Australia will be carried out by a network of computers.
68. Programming is an area of A.D.P. which is very costly. it can be expected that greatly simplified programming languages will be developed which will eliminate the lengthy periods of time now required for proaramming. The use of computers will become much simpler so far as programming is concerned.
69. In summary it may be said that the use of A.D.P. is likely to increase greatly. The technical skill required to operate computers and their peripheral equipment will become less. The general user will become more and more dependent on the software supplied with the computer, or upon the bureau or utility with which he deals.
PART 7.-COMPUTERS AND THE LAWYER
70. How much can the average lawyer reasonably hope to understand about computers? From a technical point of view, he cannot expect to understand any more about the electronic functioning of computers than he can about the functioning of a television set, the transistorized ignition and fuel injection system of a motor car or about a modern telephone exchange. All he will ordinarily know about such things is that they are complicated, they work, they sometimes go wrong and experts have to be called in to fix them.
71. The average lawyer can hardly expect to understand the logic and the mathematics which are the basis of computer design and operation. He must take the word of an expert on these matters. He has slightly more chance of understanding the mechanical devices used such as line-printers, tape drives and so forth but these have little relevance to evidentiary problems.
72. It is suggested that the only useful way for the average lawyer to approach computers and any evidentiary problems which may be caused by their use is to regard the computer as a machine which, if worked by trained persons who know what they are about, will produce useful and accurate results. He can make himself familiar in a general way with the nature of the equipment, the functions it performs, the broad principles of its operation, the role played by the various experts associated with its use, the procedures ordinarily followed in A.D.P., and the factors which may lead to error.
PART 8.-SUMMARY AND CONCLUSIONS
73. The more important of the matters mentioned in this Appendix, which are relevant to the admission in evidence of statements in business records produced by computers, may be summarized by saying that-
(1) It is generally accepted that computers can provide a reliable and accurate means of keeping and producing business records.
(2) The technical matters relevant to the operation and accuracy of computers in business are widely known and understood by the persons responsible for computer processing of business records.
(3) Statements in business records produced by computers should be reliable if the information from which the statement was derived is reliable.
(4) The use of Computers in business is now widespread and is likely to increase.
(5) Much of the use of computers is and will be by time sharing or by remote batch processing. In these procedures the user does not control the operation of the computer.
(6) There have been, and are likely in the future to be, dramatic technical changes in computers and associated equipment. It is likely that the reliability of programming will come increasingly to rest upon the provision by the manufacturer of reliable and appropriate software. It is possible that a demand for faster methods of putting information into computers may lead to acceptance of methods which are not so reliable as those hitherto most commonly used.
74. The main conclusions to be drawn from the matters mentioned in this appendix are that-
(1) There is a need for a statutory provision facilitating the admission of statements in business records produced by computers. Without such a provision a large section of business and government would continue to be deprived of admissible evidence essential to the establishment of its legal rights in litigation.
(2) Any such provision should be in general terms and not tied to any particular technical requirements.
(3) In drafting any such provision, conditions should be imposed to safeguard the reliability of the source material.
(4) For practical reasons, it is essential to relieve businesses using computers from the burden of proving strictly in legal proceedings the various steds involved in the keeping of their records. To prove such matters strictly would generally require calling numerous witnesses, including experts to explain the operation of the computers often employees of an outside computer bureau or utility, and sometimes persons engaged in distant places or other States in the keeping of the records in question. This would cause expense and disruption of business and be of no practical benefit to the parties or to the court.
(5) A person holding a responsible position in relation to the keeping of the records of a business by the use of a computer should be able to give reliable evidence, even though some of it is on information and belief, as to the system involved and other similar matters which are relevant to the admissibility of the records as evidence in legal proceedings.
(6) A party to legal proceedings against whom business records kept by a computer are tendered as evidence should have an opportunity of testing the reliability of the records by cross-examination of a person holding a responsible position in relation to the keeping of the records.
FOOTNOTES
1 We are not aware of any simple published explanation of how computers work. This appendix is based on information gathered from a number of sources. We have been greatly assisted by the Automatic Data Processing Bureau of the New South Wales Treasury. A Commissioner and a research officer attended a course of instruction at the Bureau. Senior officers of the Bureau kindly read this appendix in draft form and made a number of suggestions. Any errors which remain are our responsibility. We have also been assisted by the A.M.P. Society, the Bank of N.S.W., the Sydney Stock Exchange Ltd and I.B.M. (Aust.) Ltd. We have referred to a number of publications and in particular to: Electronic Computers, S. H. Hollingdale and G. C. Toothill, Pelican Books, 1970; Computers atid the Lawyer, Institute of Criminology, Faculty of Law, University of Sydney, 1968; Computers and the Law, ed. R. P. Bigelow, published by the Standing Committee on Law and Technology, American Bar Association, Commerce Clearing House Inc., 2nd ed., 1969.
2 The binary system works like the decimal system, except that instead of moving to the next column to the left every time you reach a multiple of 10, you do so every time you reach a multiple of 2. Thus 1 in the decimal system is 0001, 2 is 0010, 7 is 0111, 10 is 1010. The extra O’s are added to keep the binary counterpart of each conventional digit the same length.
3 See part 2.
4 Para. 13.
5 See para. 10.
6 See para. 47.
7 Described as at November, 1971.
8 The “files” mentioned may consist of more than one tape.
9 described as at November, 1971.
10 See the proposed new section 14CB in Appendix A.
11 Para. 38.
12 See the proposed section 14CK (1) (c) in Appendix A.
13 Para. 35.
14 See the proposed s. 14CB in Appendix A.
15 See the proposed s. 14CK (1) (c) in Appendix A.
|
