DATMAK is used to create the basic RT data file required by UPDATE (see Section 8). This file initially contains descriptive comments, parameters and assignment of items to conditions. Space is reserved for item and subject means. Raw data is appended to the .DAT file by UPDATE. For a full description of the two different formats for a data file, see "Structure of Data Files".
DATMAK may also be used for resetting or modifying the parameters of existing data files for reanalysis by UPDATE or creating new data files which are complete or partial copies of existing data files.
Place your disk in a free drive. If necessary, change the default drive to the drive containing your disk by typing A: or B: as appropriate (the default drive is the one named in the prompt from the operating system). Then run the program by typing
in response to the prompt. The program will respond by typing out its name and version number as well as the current date.
Operation is largely self explanatory, but a more detailed description of the responses to questions is listed below.
The program will type
INPUT FILE (IF ANY):
OUTPUT FILE :
If there is no input file, just enter a <cr> for the first prompt.
If only an output file name is entered, the program will create a new data file with that name (provided that a file with that name does not already exist on the same disk) and ask for input of the appropriate parameters.
If both an input and an output file are entered, for example:
INPUT FILE (IF ANY): FILEA
OUTPUT FILE : FILEB
the program will create a new file, FILEB, using some or all of the information present in FILEA.
If the output filename (FILEB in this example) is the same as the name of an existing file on the same disk, the program asks:
OVERWRITE EXISTING FILE? (N/Y):
If the response to this question is N (for NO), the program will ask for a new output filename.
If the response is Y (for YES), the existing file will be deleted:
1) immediately if input and output filenames are different. (Typing control C before the end of the program will not undo this.)
2) at program termination if input and output filenames are the same.
(If input and output filenames are identical, output is sent to a temporary file called $$DATMAK.TMP. At program termination, the input file is deleted and the name of the temporary file is changed to the input/output filename.)
If you enter the file names without any extension, DATMAK will append the default extension .DAT
If both input and output files are specified, as in the example above, the program will type:
UNMODIFIED REANALYSIS? (N/Y):
If the response is YES, the program will create a file, FILEB, which is an exact copy of FILEA, except that the subject and item means will be zeroed and the "inclusion flag" on each set of subject data which has been incorporated will be reset to zero. That is, the file will be set up for complete reanalysis by UPDATE.
The program will also ask:
INCLUDE PREVIOUSLY REJECTED SUBJECTS? (N/Y):
If the response is NO, the inclusion flags of only those subjects that have been included in the first analysis will be reset. Rejected subjects will not be included. This is normally what would be required. If for some reason it is desired to include previously rejected subjects, respond YES to this question.
If the response NO is given to the question
UNMODIFIED REANALYSIS? (N/Y):
when both input and output file names are entered, the input file will be copied to the output file with or without modifications, as specified by the user. The program asks whether each set of parameters is to be changed. If not the old values are retained; if so, new values are accepted in the usual way (see 5.6 below).
Valid responses are:
"N" - Retain value(s) specified in the input file.
"Y" - Accept new values for parameter(s).
"T" - Type the values of the parameters in the input file and then ask
whether these are to be changed. If so, accept the new values.
Throughout DATMAK, wherever a question is followed by a list of valid responses (e.g. N/Y or N/Y/T), the reponse listed first is the default response for that question.
If the item numbers are to be changed, this may be done for all conditions in order, or only for those conditions specified by the user.
If the number of items in each condition has been changed this will also change the assignment of item numbers to conditions. Hence it is always necessary to verify the item numbers in this case.
(a) Title and Comments
Any ASCII characters are permissible (including CR, LF, TAB, etc.). This should contain the title of the experiment, and a description of the conditions involved in the experiment, as well as any other relevant information. This information will be printed out at the beginning of each run of UPDATE when no DTP exists.
The maximum number of characters which may be entered is 448, and a warning message is printed after each line once more than 390 have been entered.If more than 448 are entered, the line will be truncated at that point. (Delete performs its usual function.)
The comments are terminated by entering Control Q <CR>.
(b) Choice of data file format
There are two different formats for .DAT files. Format 1 .DAT files consists of 8 blocks of parameters etc. and 1 block for each set of subject data. Format 2 .DAT files have 11 blocks of parameters etc. and 2 blocks for each set of subject data. (By local convention, the word "block" refers to a chunk of 256 words or 512 bytes of disk space; see "Structure of data files" for more details.)
If you have specified an input file, the output file format will automatically be the same as that of the input file. If you have not specified an input file, the program will now ask you
DOES ANY ITEM NUMBER IN THE ITEM FILE EXCEED 255? (N/Y):
If you respond YES, a format 2 data file will be created; otherwise, a format 1 data file will be created.
(c) Number of Items
Must be equal to the total number of items in all the conditions specified. If some items are not to be included in the analysis (e.g. practice items) and they have not been assigned a condition, do not include them in the total number. If an item is included multiply in a condition or a number of conditions, count each time it is included.
The maximum number of items allowed is 255 (format 1 files) or 511 (format 2 files).
(d) Number of Experimental Conditions
Must be from 1 to 25.
(e) Number of Items in Each Condition
A number or a comma must be entered for every condition. 1st number is condition 1, 2nd is condition 2 etc. If a condition size is zero, or omitted by the use of multiple commas, it will be set equal to the last non-zero condition size preceding it.
For example, if there are 9 conditions in the experiment, the commands on the left below will lead to the sets of condition sizes on the right:
5,,,,,,,,, 5 5 5 5 5 5 5 5 5
5,10,15,10,,,,,, 5 10 15 10 10 10 10 10 10
7,0,0,0,5,0,0,8,, 7 7 7 7 5 5 5 8 8
7,,,,5,,,8,, 7 7 7 7 5 5 5 8 8
Until a number or a comma has been specified for every condition, the program waits for further entries. Any excess commas entered will be ignored.
If the total number of items specified matches the sum of the number of items in each condition, the program types the values and asks for verification. If not, the number of items and conditions must be entered again.
(f) Standard Deviation (SD) Cutoff
If blank or less than 0.001 this will default to 2.00 standard deviations. If a cutoff is not required, 9.99 should be entered. If a cutoff other than default is specified the program will request verification of it.
(g) Absolute Lower Cutoff
If not specified this will default to zero, which is equivalent to not using the cutoff. If a value is specified, all reaction times which are less than or equal to the cutoff will be treated as missing data by UPDATE, i.e. will not be included in the analysis. The actual raw data matrix of each subject however will not be changed by this.
(h) Absolute Upper Cutoff
Specifying an integer value imposes an upper cutoff on RTs. Any value greater than this value will be assumed equal to it in the analysis. Again the raw data is not changed.
(i) Disk Storage Scaling Factor
DATMAK automatically sets the disk storage scaling factor to 1 without consulting the user. Following improvements in the method of calculating item means in UPDATE, it is no longer necessary to have a scaling factor greater than 1.
(j) Item Numbers in Each of the Conditions
These should be entered, separated by commas, for each condition as requested. They must be between 1 & 250. A number or a comma must be entered for every item in the condition being entered. Until this is done, the program waits for more input.
If sequential numbering is used in each condition, this procedure can be vastly simplified. If an item number is specified as comma or zero, it will be set equal to the previous item number plus one. Thus it is possible to enter a sequence of item numbers merely by specifying the first number in the sequence. This may apply to the whole condition, or only some part of it. For example if there are 10 items in a condition, the commands on the left will lead to the sets of item numbers on the right.
11,,,,,,,,,, 11 12 13 14 15 16 17 18 19 20
2,3,6,21,,,,,,, 2 3 6 21 22 23 24 25 26 27
1,0,0,0,15,,,,,, 1 2 3 4 15 16 17 18 19 20
1,,,,15,,,,,, 1 2 3 4 15 16 17 18 19 20
1,,,99,73,11,,,31,, 1 2 3 99 73 11 12 13 31 32
Once the item numbers for a condition have been entered the program will type them out and request verification before going on to the next condition. If they are incorrect it will request them again.
When the input file contains subject data, there is the option of either including or excluding this in the output file. The program will ask:
IS SUBJECT DATA TO BE INCLUDED? (N/Y)
If the subject data is included it will always be reanalysed.
WARNING: If the input and output files have the same name and extension, the input file will be deleted on termination of the program. Thus, if you have said that the subject data is not to be included in the output file, it will be lost completely under these circumstances. If this is the case the program will print out a warning and request verification before deleting the data:
*WARNING* SAME FILE NAME; ARE YOU CERTAIN? (N/Y):
If you reply YES, the subject data is lost.
If you reply NO, the subject data will be included.
If you type control C at this point, the input file will be left as it was before you started DATMAK.
(a) Non Fatal Errors
(WARNING - ONLY nn MORE CHARACTERS MAY BE ENTERED) This message appears on the screen after each line of comments is entered when the remaining storage is sufficient for 58 characters or less. Note that the <cr> at the end of each line counts as two characters.
FILE NOT FOUND
File name specified was not on the disk. Re-enter file name.
ILLEGAL FILE NAME
The file name has too many characters.
(WARNING - COMMENT OVERFLOW-LINE TRUNCATED)
Last line of comments exceeded the amount of storage space allocated and has been partially cut. If satisfactory continue, otherwise abort run and start again.
?MINIMUM 0, MAXIMUM 255? / ?MINIMUM 0, MAXIMUM 511?
No. of items must be within the specified range. Re-enter or abort.
Maximum number of conditions is 25. Re-enter or abort.
?ITEM NO. MISMATCH?
Sum of all condition sizes did not match total number of items. Re-enter data.
?ITEM NUMBERS MUST NOT EXCEED 255/511?
Item numbers are not allowed to exceed the specified value, which depends on the format of the data file.
*WARNING* - SAME FILE NAME, ARE YOU CERTAIN?
Input and output files have the same name. Input file will therefore be deleted, and if the subject data is not included in output file, it will be lost.
All other non-fatal errors are warnings and are self explanatory.
(b) Fatal Errors
DATMAK I/O ERROR nnn
An error occurred in reading or writing the disk. nnn indicates where in the program the problem is. Get help if you see this message.