This management summary contains some content which was originally
presented in Professor Peter Saville’s Keynote Speeches at:
The British Psychological Society Division of Occupational Psychology
Conference, Stratford-upon-Avon, January 2008: “Personality
Questionnaires – Valid Inferences, False Prophecies”
The Psychological Society of South Africa Annual Conference,
Johannesburg, August 2008: “Does Your Test Work?”
A&DC Conference, Institute of Directors, London, November 2008:
“A Comparison of Leadership in Business and Elite Athletes”
© 2008 Saville Consulting. All rights reserved.
1
Project Epsom:
How Valid Is Your Questionnaire?
Management Summary: A New Comparative Study of the Major
Personality Questionnaires in Predicting Job Performance
Professor Peter Saville, Rab MacIver, Dr Rainer Kurz & Tom Hopton
Overview
● The Saville Consulting Wave® Professional Styles questionnaire
was the most valid assessment for measuring work performance, in
a major study of 308 participants who completed a range of popular
personality questionnaires
● Wave Focus Styles and the newly-developed Saville Personality
Questionnaire (Saville PQ™), comparable with the Occupational
Personality Questionnaire (OPQ®), were found to be at least as
valid, if not more so, than the OPQ32i
● Compared to the OPQ32i, the Saville PQ uses more modern
technology, takes about 13 rather than 60 minutes to complete,
gives both normative and ipsative scores and measures both
workplace motives and talents
● Using more valid questionnaires can dramatically reduce selection
errors with great impact on company profitability
The Study
● Questionnaires were compared against the same independent work
performance criteria. These were:
- A global performance measure of Accomplishing Objectives,
Applying Specialist Knowledge and Demonstrating potential
- The SHL Great Eight work competencies
● Measures of participants’ work performance were established
by asking third-parties to independently rate how effectively the
participants performed in the work competencies covered by the
Great Eight and global performance criteria
● The more accurately a personality questionnaire predicts how
independent raters have judged the work performance of the
participant in a completely separate rating form, the more valid the
personality questionnaire
© 2008 Saville Consulting. All rights reserved.
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● The most important aspect of a questionnaire is its validity for
measuring and predicting work performance
● Validity is shown as a correlation coefficient between -1 and +1. A
validity of 0 indicates chance measurement and is as effective as
flipping a coin to predict a persons job performance. A validity of
+1 is perfect measurement of job performance but is impossible to
achieve in practice. A validity of +0.3, although seemingly low, can
offer high financial gain and can cut selection errors by half or more
● Studies generally indicate that a good personality questionnaire can
have a validity of +0.3. Validities above +0.7 for any technique are
virtually unknown in the literature
● Higher validities significantly reduce selection errors
● Ability tests have validities of around +0.5; unstructured interviews
around +0.2. Educational qualifications are surprisingly poor
predictors of performance, at around +0.1
● For the purposes of this summary, we report validity results from
seven key questionnaires:
- Saville Consulting Wave® Professional Styles (Wave
Professional)
- Saville Consulting Wave® Focus Styles (Wave Focus)
- Saville Personality Questionnaire (Saville PQ)
- Occupational Personality Questionnaire® (OPQ32i)
- 16 Personality Factor Questionnaire (16PF5)
- Hogan Personality Inventory (Hogan PI)
- NEO Personality Inventory (NEO)
● These seven key questionnaires were compared against the
external ratings of global work performance
● They were then compared against the external ratings of the SHL
Great Eight work performance competencies
© 2008 Saville Consulting. All rights reserved.
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Results
Figure 1. The validity of seven key questionnaires
in measuring global work performance.
Matched Sample of N=308 against external ratings on Global Performance
(Applying Specialist Expertise, Accomplishing Objectives,
Demonstrating Potential)
0.6
High
Validity
0.5
0.4
Moderate
Validity
0.3
0.2
0.1
Wave
Professional
Wave Focus
NEO
Saville PQ
Hogan PI
16PF5
0
OPQ32i
Chance
● All of the seven questionnaires show at least a moderate level of
validity in predicting work performance according to the global work
performance criteria
● Saville Consulting Wave Professional Styles comprehensively
outperforms all other questionnaires in terms of validity
● Wave Focus Styles and the Saville PQ take under 15 minutes each
to complete yet compare favourably in terms of validity with much
longer questionnaires such as the OPQ32i, the Hogan Personality
Inventory and the 16PF5
© 2008 Saville Consulting. All rights reserved.
4
Figure 2. The average validity of seven key questionnaires
in measuring the Great Eight competencies.
The average validity in predicting SHL’s Great Eight.
Matched Sample of 308.
0.6
High
Validity
0.5
0.4
Moderate 0.3
Validity 0.2
0.1
Wave
Professional
Wave Focus
Saville PQ
NEO
OPQ32i
Hogan PI
0
16PF5
Chance
● The Saville Consulting questionnaires are the most valid
questionnaires for measuring work performance in Project Epsom,
even when validity is defined by the independent SHL Great Eight
measures of work performance
● Saville Consulting questionnaires are strong in terms of validity
compared with the OPQ, even against SHL’s own model of work
© 2008 Saville Consulting. All rights reserved.
5
Figure 3. The power of seven key questionnaires
in terms of their delivery of validity in 15 minutes.
Matched Sample of 308
0.6
Valid Power
0.5
0.4
0.3
0.2
0.1
Wave Focus
Saville PQ
Wave
Professional
16PF5
Hogan PI
NEO
OPQ32i
0
● “Power” relates to measuring effectiveness or output in a given unit
of time. In terms of personality questionnaires, it can relate to the
questionnaire which provides the greatest validity per unit of time.
Figure 3 compares the power of the tests in terms of how much
validity can be achieved by each in 15 minutes
● The Wave Focus Styles and Saville PQ questionnaires are the most
powerful, offering high validity in the shortest completion times
● Other questionnaires in Project Epsom are the subject of future
reports, academic papers and presentations, but briefly:
- With the DISC questionnaire, no evidence could be found for
the validities of +0.75-0.95 which were claimed on the Thomas
International Website
- The Hogan Development Survey, which assesses the “Dark
Side” of personality, failed to relate positively or negatively
to work performance. Only 8% of participants retained their
exact Dark Side profile when they re-completed the same
questionnaire after just one week
© 2008 Saville Consulting. All rights reserved.
6
Increasing Validity Increases Return on Investment
● Questionnaires of high validity increase the chance of selecting
better work performers; considerably reducing selection errors
● An example of a serious selection error is selecting a candidate
from the bottom 20% of performers when you mean to select from
the top 20% of performers
- If a questionnaire has a validity of +0.3, one person in every ten
that you select will prove to be in the bottom 20% of performers
- If a questionnaire has a validity of +0.6, one person in every fifty
that you select will prove to be in the bottom 20% of performers
● Moving from recruiting using a questionnaire with a validity of +0.2
to using a questionnaire with a validity of +0.4 can double the costbenefit to an organization
● It can reduce the number of serious selection errors five-fold,
remarkably improving the accuracy of the selection process
Conclusions
● The Saville Consulting questionnaires maximise the measurement
of performance at work, assessing work-specific competencies
which are relevant to modern business life
● Some other questionnaires, perhaps developed half a century ago:
- measure out of date aspects of work performance
- have work-irrelevant clinical scales of poor validity
- use obscure and badly-written questions
● Cost savings from using better tests can be “startlingly large”.
Neither employer nor employee gains from poor selection
● When the participants were followed up after six months, essentially
the same questionnaire rank order of validity was maintained
with Saville Consulting Professional Styles and Focus Styles
outperforming the other questionnaires
© 2008 Saville Consulting. All rights reserved.
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The Full Project Epsom Phase One Paper
This document offers a brief management summary of the major
Saville Consulting research programme, Project Epsom. A full version
of this research paper is available online and in hardcopy and further
details can be found at www.savilleconsulting.com, or by calling
+44(0)1534 726820 or +44(0)1372 475700.
References to accompany this Management Summary are in the full
version of this paper, “How Valid is Your Questionnaire?”, available
from www.savilleconsulting.com.
Copyright Permissions
© 2008 Saville Consulting. All rights reserved.
This summary is available in hard-copy format and online at
www.savilleconsulting.com. The authors give permission to copy, print,
or distribute this research paper provided that:
1.
each copy makes clear who the research paper’s authors are;
2.
each copy acknowledges that this paper was produced through
research endeavour by Saville Consulting;
3.
copies are not altered without the consent of the senior author.
© 2008 Saville Consulting. All rights reserved.
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