DMDX Help.


Input Overview.


    Input signals in DMDX are divided into five groups of which only three are relevant these days, request signals, positive response signals and negative response signals (the two others being tape pulse signals and voice key signals).  Request signals dismiss instructions (items that have zero for an item number that don't gather responses) as well as make DMDX proceed to the next item after gathering an RT in items that don't automatically continue to the next item.  Positive and negative response signals generate RTs.  Multiple signals (or button presses) can be mapped to the same input group, however one signal cannot be mapped to multiple input groups unless the <mip multisignal> command has been given (useful for having a space bar mapped as a request as well as a positive response).
    There are multiple different ways for DMDX to record a subject's data beyond Dmastr's original simple binary RT (reaction time) switch closure mode.  DMDX can take input from numerous devices including sounds cards for vocal responses.  Originally back in the PDP-11 days data was stored in a binary array written to disk as a .DTP file with a quite limited range of item numbers and RTs only up to 32 seconds.  DMDX's predecessor DMTG introduced the .AZK file format that is now the default output file format where item numbers are valid to 9 digits and RTs to days.  However the .AZK file format is still a simple RT data format, to handle more elaborate input modes the .ZIL file format is used to store zillions of responses.  When zillions of responses are used the standard DMDX data analysis package Analyze.exe is no longer usable as it only reads .AZK files, all data will have to analyzed by the user.  Also when zillion responses are used all key press and release data is stored unless deliberately limited.  Zillion responses come with several different modes, one designed to facilitate ratings, another designed to facilitate typed responses (although for simply inputting a subjects name or long blocks of prose avoiding <zil> and using <prose> instead probably makes more sense).  Looking time studies are possible.



DMDX Index.