HTS Report

d2-R
Test of Attention – Revised
Technical Report

Another Sample
ID 467-500
Date 14/04/2016

© Hogrefe Verlag, Göttingen

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OVERVIEW

Structure of this report

Narrative
Introduction
Verbal interpretation of standardised scores
Results
Profile sheet
Table of scores
Scale details

Only qualified psychologists or appropriately trained test administrators should interpret psychometric test results. Please follow the
relevant guidelines from the appropriate professional body.

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Assessment date 14/04/2016 | Age 46;0* | Gender m © Hogrefe Verlag, Göttingen
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INTRODUCTION

The test
The online d2-R is the computerised version of the d2 Test of Attention – Revised (Brickenkamp,
Schmidt-Atzert & Liepmann, 2016). The test measures the ability to concentrate and sustain attention.
The task is to pick out target symbols, from among similar symbols, under pressure of time. The test
stands out for its accuracy of measurement, and there is extensive evidence that it does indeed
measure the constructs of attention and concentration.
The online version is closely aligned with its paper and pencil counterpart. The test taker is asked to
search for and mark certain target symbols on the screen: instances of the letter ‘d’ with two dashes.
The instructions explicitly introduce all three variants of the target (both dashes above, both dashes
below, one dash above and one dash below) and they also show the different distractors (‘p’ with a
number of dashes, ‘d’ with other than two dashes). A symbol is marked by moving the mouse over it
and left-clicking (or, on a touchscreen, by tapping the symbol with a finger); this draws a diagonal line
through the symbol, as though it had been crossed out with a pencil. Symbols are processed from left
to right, one row at a time. The task is first practised without a time limit. At this stage, the test taker is
alerted to every error and asked to correct it at once (a wrong mark is removed with a second click or
finger tap). The task is then practised with a time limit. Now feedback occurs at the end: all errors are
flagged and must be corrected before the test can begin.
The test itself consists of 14 screens in succession, each having 60 symbols laid out in six rows of
ten. All instances of ‘d’ with two dashes are to be marked. The instruction is to work quickly, without
making mistakes. Processing time is limited to 20 seconds per screen, with a one-second pause
between screens.

Three main variables are computed and then reported as norm-referenced scores:
• Concentration Performance (CP). This score is defined as the number of ‘hits’ (targets which
were marked, PT − EO) minus the number of distractors which were marked (errors of
commission, EC). The CP score is a measure of processing speed adjusted for errors made.
• Processed Targets (PT). This is the number of target symbols in the ‘processed’ portion of the
test: up to and including the last response marked on each screen. It equals the number of
‘hits’ (targets found) plus the number of targets which were overlooked (EO). The PT score is a
measure of processing speed without consideration of accuracy.
• Accuracy (E%). The raw score is the ‘relative’ error rate, determined by dividing the total number
of errors (errors of omission and commission, EO + EC) by the number of processed targets
(PT), and expressing this fraction as a percentage. This score is then norm-referenced in
reverse, so that a high standard score reflects highly accurate responding.

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For three further variables, only raw scores are reported:
• Errors of Omission (EO). This is the number of targets that the test taker ‘processed’ (see above)
but omitted to mark. These mistakes are easily made, so they occur often. The raw error rate E%
(see above) is usually close to the omission rate, since errors of commission rarely occur.
• Errors of Commission (EC). This counts how often the test taker marked a distractor (‘d’ with the
wrong number of dashes or any instance of ‘p’). These errors are generally rare in d2-R test
taking. If several of these errors occur, this may indicate that the test taker’s approach was not in
accordance with the instructions. If a test taker selects symbols arbitrarily, EC will be very large
(usually well over 100).
• Errors of Commission of ‘Letter’ type (ECL). These are the errors of commission in which only the
letter was wrong (letter ‘p’ with two dashes). In general, test takers find ‘p’ easier to avoid than ‘d’
with a wrong number of dashes. Elevated ECL scores are particularly indicative of the
instructions not being adhered to.

Validity checks
Certain unusual score patterns may indicate that the participant responded in an uncooperative or
non-regulation manner. If such patterns are found, this is flagged up in the ‘Table of scores’ later in
this report. The following patterns are checked for:
• Symbols seemingly marked at random (arbitrarily). In such cases, errors of commission will be
extremely frequent (EC > 100 if working quickly) and the CP raw score will generally be negative.
This is because the test has considerably more distractors than targets. If symbols are marked at
random, errors of commission (EC) almost certainly outnumber correctly processed targets (PT –
EO), leading to a negative CP raw score (CP = PT – EO – EC). Random responding can occur if
the instructions were not understood or remembered, or if the test taker was not cooperative.
• Simulation of low performance. Test takers trying to fake low performance usually commit
conspicuously many errors of ‘letter’ type (ECL at least two, rarely more than twenty). The total
number of errors of commission (EC) is usually elevated, because some instances of ‘d’ with the
wrong number of dashes are deliberately marked. If the CP raw score is negative, however, this
suggests random responding rather than faking.

Graphical illustration of standardised scores

Standardised scores consider a test taker’s performance in the context of a suitable reference group
of other people (also known as the norm group). The reference group used in this report was ‘UK
population, male and female, 18–55 years’.
At the very end of this report (in the section entitled ‘Scale details’) the three standardised d2-R
scores are illustrated graphically. In these graphs, the test performances of the reference group are
displayed as so-called normal curves, and the test taker’s score is plotted as a red line.
The horizontal axis represents test performance on the T-score scale from 20 to 80. This scale is
calibrated such that its midpoint of 50 is the average score for the reference group. The more a
performance exceeds this average, the further right along the axis it appears. Performances lower

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than average appear to the left.
The height of the curve shows how frequently each score occurred in the reference group. Scores
close to average are very common; hence the curve is highest in the middle. Scores become rarer the
more they differ from average, so the curve falls away to both sides.
The graph shows at a glance whether the test taker’s score (red line) was above or below average,
and by how much. It is also makes visible what proportion of individuals in the reference group had
higher or lower test scores. This is shown by the area under the curve to the left or right of the red
line. If the line is in the middle (at 50), then 50 per cent of the reference group have higher test scores
and 50 per cent have lower test scores. About 68 per cent of all test scores fall within the range 40 to
60, and about 95 per cent of all scores fall within the range 30 to 70. If a test taker scores 70, only
about 2.5 per cent of the reference group will have attained even higher test scores. The area under
the curve to the right of 70 makes up approximately 2.5 per cent of the total area.
Brickenkamp, R., Schmidt-Atzert, L. & Liepmann, D. (2016). The d2 Test of Attention – Revised. A Test of
Attention and Concentration. Oxford: Hogrefe.

VERBAL INTERPRETATION OF STANDARDISED SCORES

This report follows the suggestions in the d2-R test manual for assigning verbal score bands to
standardised scores. Scores within half a standard deviation of the mean score are classified as ‘in
the average range’. Scores outside this range are considered ‘high’ or ‘low’. Scores that lie more than
one and a half standard deviations from the mean are considered ‘very high’ or ‘very low’. When using
the T-score scale, this leads to the following classification:
• A T-score below 35 is significantly below average. A performance in this range can be interpreted
as ‘very low’. Approximately 7 per cent of the reference group obtained scores in this range.
• T-scores between 35 and 44 can be classified as below average. Performances in this range can
be referred to as ‘low’. About 24 per cent of the reference group obtained scores in this range.
• T-scores between 45 and 55 are classified as ‘in the average range’. A performance in this range
can be regarded as ‘average’. This range comprises about 38 per cent of the reference group.
• T-scores between 56 and 65 can be classified as above average. Performances in this range can
be interpreted as ‘high’. About 24 per cent of the reference group obtained scores in this range.
• A T-score over 65 is significantly above average. The performance can be described as ‘very
high’. Approximately 7 per cent of the reference group obtained scores in this range.

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RESULTS
Reference group: ‘UK population, male and female, 18–55 years’.

Principal scores and interpretation

T very low low average high very high

68 CP Concentration Performance
64 PT Processed Targets
64 E% Accuracy

CP Concentration Performance
The score achieved on the Concentration Performance scale (CP) can be classified as very high.
Compared with the reference group, the test taker’s error-corrected pace of work in the d2-R was well
above average. The result suggests a very high ability to concentrate when compared with this group.

PT Processed Targets
The score achieved on the Processed Targets scale (PT) can be classified as high. The number of
target symbols processed by the test taker was above average when compared with the reference
group. The result suggests a high pace of working.

E% Accuracy
The score achieved on the Accuracy scale (E%) can be classified as high. In other words, compared
to people in the reference group, the test taker showed a below-average error rate. The result
suggests a high accuracy of working.

Evolution of CP and E% during the test: raw scores for each screen of symbols

CP E%

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Accuracy vs Speed (E% in relation to PT)

The working style exhibited by the test taker during the test is summarised in the following diagram.
The horizontal axis shows the T-score achieved on the Processed Targets scale (PT), indicating the
test taker’s working speed compared to the reference group. The vertical axis shows the T-score
achieved for Accuracy (E%). The white central square illustrates the average range for the reference
group (T-scores from 45 to 55).

Compared to the reference group, the test taker’s working style during the d2-R can be classified as
high in both speed and accuracy.

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Assessment date 14/04/2016 | Age 46;0* | Gender m © Hogrefe Verlag, Göttingen
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PROFILE SHEET

d2 Test of Attention – Revised |

UK population, male and female, 18–55 years - T Score (50+10z)

Overall results
270 68 CP Concentration Performance
Processing speed after adjusting
for errors made. Raw score
equals number of targets found
minus number of distractors
marked.
276 64 PT Processed Targets
Processing speed irrespective of
errors made. Raw score counts
how many target symbols occur
in the processed portion of the
test.
2.2 64 E% Accuracy
Normed score measures
accuracy: high scores reflect a
low error rate. Raw score is error
rate: errors as percentage of
processed targets.

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TABLE OF SCORES

d2 Test of Attention – Revised |

UK population, male and female, 18–55 years - T Score (50+10z)

Scale Raw val Normed val

Overall results
CP Concentration Performance 270 68
PT Processed Targets 276 64
E% Accuracy 2.2 64
EO Errors of Omission 0
EC Errors of Commission 6
4
ECL Errors of Commission of ‘Letter’ type Raw score suggests simulation of low
performance

d2 Test of Attention – Revised |

UK population, male and female, 18–55 years - T Score (50+10z)

Scale Raw val

Screen 1
01 CP Concentration Performance 21
01 PT Processed Targets 24
01 E% Error Rate 13
01 EO Errors of Omission 1
01 EC Errors of Commission 2
01 ECL Errors of Commission of ‘Letter’ type 1
Screen 2
02 CP Concentration Performance 10
02 PT Processed Targets 11
02 E% Error Rate 9
02 EO Errors of Omission 0
02 EC Errors of Commission 1
02 ECL Errors of Commission of ‘Letter’ type 0

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d2 Test of Attention – Revised |
UK population, male and female, 18–55 years - T Score (50+10z)

Scale Raw val

Screen 3
03 CP Concentration Performance 12
03 PT Processed Targets 13
03 E% Error Rate 8
03 EO Errors of Omission 0
03 EC Errors of Commission 1
03 ECL Errors of Commission of ‘Letter’ type 1
Screen 4
04 CP Concentration Performance 21
04 PT Processed Targets 22
04 E% Error Rate 5
04 EO Errors of Omission 0
04 EC Errors of Commission 1
04 ECL Errors of Commission of ‘Letter’ type 1
Screen 5
05 CP Concentration Performance 21
05 PT Processed Targets 22
05 E% Error Rate 5
05 EO Errors of Omission 0
05 EC Errors of Commission 1
05 ECL Errors of Commission of ‘Letter’ type 0
Screen 6
06 CP Concentration Performance 25
06 PT Processed Targets 25
06 E% Error Rate 0
06 EO Errors of Omission 0
06 EC Errors of Commission 0
06 ECL Errors of Commission of ‘Letter’ type 0

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d2 Test of Attention – Revised |
UK population, male and female, 18–55 years - T Score (50+10z)

Scale Raw val

Screen 7
07 CP Concentration Performance 19
07 PT Processed Targets 19
07 E% Error Rate 0
07 EO Errors of Omission 0
07 EC Errors of Commission 0
07 ECL Errors of Commission of ‘Letter’ type 0
Screen 8
08 CP Concentration Performance 24
08 PT Processed Targets 24
08 E% Error Rate 0
08 EO Errors of Omission 0
08 EC Errors of Commission 0
08 ECL Errors of Commission of ‘Letter’ type 0
Screen 9
09 CP Concentration Performance 22
09 PT Processed Targets 23
09 E% Error Rate 4
09 EO Errors of Omission 0
09 EC Errors of Commission 1
09 ECL Errors of Commission of ‘Letter’ type 1
Screen 10
10 CP Concentration Performance 22
10 PT Processed Targets 22
10 E% Error Rate 0
10 EO Errors of Omission 0
10 EC Errors of Commission 0
10 ECL Errors of Commission of ‘Letter’ type 0

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d2 Test of Attention – Revised |
UK population, male and female, 18–55 years - T Score (50+10z)

Scale Raw val

Screen 11
11 CP Concentration Performance 21
11 PT Processed Targets 22
11 E% Error Rate 5
11 EO Errors of Omission 0
11 EC Errors of Commission 1
11 ECL Errors of Commission of ‘Letter’ type 1
Screen 12
12 CP Concentration Performance 26
12 PT Processed Targets 26
12 E% Error Rate 0
12 EO Errors of Omission 0
12 EC Errors of Commission 0
12 ECL Errors of Commission of ‘Letter’ type 0
Screen 13
13 CP Concentration Performance 20
13 PT Processed Targets 20
13 E% Error Rate 0
13 EO Errors of Omission 0
13 EC Errors of Commission 0
13 ECL Errors of Commission of ‘Letter’ type 0
Screen 14
14 CP Concentration Performance 27
14 PT Processed Targets 27
14 E% Error Rate 0
14 EO Errors of Omission 0
14 EC Errors of Commission 0
14 ECL Errors of Commission of ‘Letter’ type 0

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SCALE DETAILS

CP Concentration Performance
UK population, male and female, 18–55 years - T Score (50+10z)

Raw val 270

Normed val 68
Confidence interval [65 - 71]

This parameter describes the ability to concentrate. It depends on the speed at which the test was
processed and, to a lesser extent, on the number of errors. The score is defined as the number of
target symbols which were found (PT – EO) minus the number of distractors which were marked
(EC). The score cannot be inflated by skipping ahead to later portions of the test, because the
resulting increase in PT is exactly cancelled out by the increase in EO; but nor is there a penalty for
responding in such a way. The score is also relatively resistant to distortion arising from the varied
emphasis that test takers may place on speed versus accuracy.

Low Value
Low norm-referenced scores suggest a below-average ability to concentrate.

High Value
High norm-referenced scores suggest an above-average ability to concentrate.

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PT Processed Targets
UK population, male and female, 18–55 years - T Score (50+10z)

Raw val 276

Normed val 64
Confidence interval [60 - 68]

This variable captures the speed at which the test was processed. The raw score is the number of
target symbols lying in the ‘processed’ portion of the test: up to and including the last response
recorded on each screen. In this portion of test, targets that were found have obviously been
processed, and targets that were not found are assumed to have been processed too, just not
carefully enough. Thus, PT equals the number of ‘hits’ (targets found) plus the number of targets
which were overlooked (EO). If the test is processed without mistakes, the PT and CP raw scores
are the same.

Low Value
Low norm-referenced scores may indicate that the test taker is comparatively slow at processing
simple tasks. However, processing speed is partly influenced by how much emphasis is put on
accuracy. For example, a test taker may consciously choose to work especially slowly in order to
minimise the number of mistakes.

High Value
High norm-referenced scores may indicate that the test taker can process simple tasks very quickly.
However, if such speed came at the cost of incurring a high number of errors, then this trade-off may
indicate a processing speed that exceeded the maximum speed at which the test taker can maintain
an acceptable standard of accuracy.

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E% Accuracy
UK population, male and female, 18–55 years - T Score (50+10z)

Raw val 2.2

Normed val 64
Confidence interval [59 - 69]

E% is a measure of the accuracy with which the test was processed. The raw score is the error rate:
the total number of errors (errors of omission and errors of commission) divided by the number of
processed targets (PT) and then multiplied by 100 to express this ratio as a percentage. The larger
the raw score, the less accurate was the processing of the test. For clarity, the norm-referenced
scores are reversed: a high normed score reflects a high level of accuracy achieved during the test.

Low Value
Low norm-referenced scores may indicate that the test taker makes a higher than average number
of mistakes when processing simple tasks. However, processing accuracy is partly influenced by
how much emphasis is put on speed. Thus, working at an especially fast pace in order to process as
many symbols as possible can increase the number of mistakes.

High Value
High norm-referenced scores may indicate that the test taker performs simple tasks with a high
degree of care and accuracy. However, processing accuracy is partly influenced by how much
emphasis is put on speed. A low number of mistakes could be the result of processing the test at a
deliberately slow pace in order to minimise the error rate.

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EO Errors of Omission
Raw val 0

This is the number of targets (‘d’ with two dashes) that the test taker passed over and omitted to
mark. These errors are relatively easy to make, so they occur comparatively often.

EC Errors of Commission
Raw val 6

This is the number of distractors (‘d’ with other than two dashes, ‘p’ with any number of dashes) that
the test taker marked. In general, these errors are comparatively rare.

ECL Errors of Commission of ‘Letter’ type

Raw val 4

Raw score suggests simulation of low performance

This counts how many distractors of the form ‘p’ with two dashes were marked. In general, these
errors are rare. Elevated values may indicate that the test instructions were not being adhered to.

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Assessment date 14/04/2016 | Age 46;0* | Gender m © Hogrefe Verlag, Göttingen