The Vienna Test is a computer-assisted application of a large number of highly diverse psycho-diagnostic tests, measuring reaction times in a task that required choosing among complex stimuli.
The following is an extract from a Department Briefing to the Portfolio Committee on Defence on Psychometric Testing in the Department of Defence (DoD) held on 19 June 2007.
Research overview on the use of the VTS in the SAAF Pilot Selection Test Battery Consists of numerous subtests (27+)For Selection purposes:
- Determination Unit (DT)
For Research purposes:
- Cognitrone Test
- Two-hand coordination Test
- Pilot Spatial Test
- Time-Movement Anticipation Test
Need to include Multi-tasking subtest
Application of determination test- Measurement of reactive stress tolerance
- Ability to give sustained multiple-choice reactions to rapidly changing stimuli
- Detect attention deficit disorders and color blindness
Theoretical backgroundThe DT measures Reactive Stress Tolerance and related reaction speed ito:
- Discrimination of colours and acoustic signals,
- The memorization of the relevant characteristics of stimulus configurations and response buttons as well as assignment rules,
- The selection of the relevant reactions according to assignment rules
- Continuous, sustained rapid and varied reactions to rapidly changing stimuli
ObjectivityTest Administration
- The computer-aided implementation of tests guarantees that the instructions as well as the presentation of stimuli are equal for all subjects and independent of the test administrator
- Evaluation
Registration of data and comparison of norm samples is carried out automatically by the computer, thus the possibility of miscalculation is eliminated
- Interpretation
As the test is a standardized performance test, interpretation objectivity is evident (Lienert, 1961)
Interpretation of test resultsCorrect reactions on time
- This indicate how well a subject adapts to a pre-set presentation duration of stimuli.
- This ability (to adapt) depends on two factors:
Subjects have to pace their reaction time in such a way that they do not get off the track
They have to make sure that there is enough time in between each stimulus to make the right decision
- T-scores above 60 and below 40, (or percentiles) above 84 and below 16) demonstrate a development of this ability above or below average, respectively
- Poor performance is indicated by:
A low score of correct responses on time (compared to the norm sample)
A proportional decrease in the number of correct responses on time when the presentation time of the stimuli is diminished
Delayed and Omitted reactions
- Usually, when the presentation time of the stimuli is decreased, a growing number of reactions are first delayed, then omitted.
This results from the fact that the speed at which the stimuli are presented accounts for the most difficult condition of the test
- The initial increase in the number of delayed reactions versus omitted reactions is a normal function of our attention
This function guarantees that a reaction is screened from external distractions (in this case the interruption of the stimulus presentation) and thus is carried out even though a new stimulus appears.
- A high number of omitted reaction (T-score below 40 due to reversed scale) combined with a low number of delayed reactions (T-score under 40) would therefore indicate attention deficits.
Incorrect Reactions
- Incorrect reactions indicate the tendency to confuse stimuli
- The Response Matrix can locate where such confusions accumulate
- In contrast to delayed and omitted reactions, incorrect reactions are not so much an indicator of the difficulty of the test.
- Usually, the number of incorrect responses increases only slightly when the presentation time of the stimuli is decreased
- Incorrect reactions occur mainly because the subjects are unable to screen appropriate responses from concurrent and irrelevant external distractions
Thus, the variable “Incorrect Reactions” is closely linked to any attention deficits
- The number of incorrect reactions indicates the subject’s tendency to give a rapid response at the very last moment under the pressure of limited presentation time
The Three Phases: