Psychometric Tests are scientifically designed instruments that MEASURE psychological constructs/ capabilities like EQ and IQ. Three of their key scientific properties which will be explained shortly are:
Validity
Reliability
Normative Measures
Psychometric Tests are packaged in various ways:
Pencil and paper tests which are hand scored by a psychological professional.
Computerised test which are automatically scored.
Online tests which are also a computerised version of psychometric tests that can be administered remotely.
Psychometric Instruments can be tests of ability involving right and wrong answers where a person’s performance on a capability such as numerical problem solving is measured.
Psychometric Instruments can also take the form of inventories, where candidates choose from a list of answers that ultimately help us to learn more about their personality, values interests and so on.
Psychometric Tests measure psychological constructs like EQ and IQ
A psychological construct, simply put, is something that tells us about the psychology or inner workings and capabilities of a person. Under psychological construct we would classify things like:
These constructs regulate how a person develops competencies, utilizes them, engages with others and generally deals with the many job challenges any employee is faced with.
Measurement
It is important to note that psychometric tests measure, they do not estimate. Let us illustrate. If you pick up a brick and move it between your hands and are asked what it weighs, you can provide an estimate or judgement of what you think the brick weighs. This is how all other assessment tools - interviews, role plays, case studies etc work. They rely on observers making a SUBJECTIVE estimate or judgement about a person’s behaviour.
However, if you put the brick on a scale, you will get an accurate and objective measurement of the brick’s weight. The reading on the scale will be completely divorced from your own opinion of what the brick weighs. Unlike you or I, a scale is specifically designed to measure weight, so we can be sure that the probability is extremely high that it gives a better reading of the brick’s weight than our own estimation of it. This is how psychometric tests work. They provide measurements, not estimates of psychological constructs like EQ and IQ. There is no subjective judgement or guess work involved.
Properties of Psychometric Tests
Validity
This means that a psychometric test must prove that it measures what it purports to measure. For example, a tool that claims to measure temperature but actually measures weight, is not a valid measure of temperature. In the same way a psychometric test that claims to measure say emotional resilience, but in fact measures something else cannot be considered to be valid.
Reliability
Psychometric tests must prove that they are reliable, i.e. that they will provide a similar result on a later measurement. For example, if you put a brick on a scale and it weighs 2kg today, and you put the same brick on the same scale tomorrow, but now it weighs 3kg then that scale cannot be said to be reliable.
Example
If a test claims to measure something like emotional resilience, and the test is both valid and reliable, we know with a high degree of confidence, that the test is in fact measuring resilience and not something else. We also know that if a candidate repeats the test sometime in the future, we will find a similar measurement to the original. The test is stable and does not fluctuate wildly in its measurements. Other assessment tools such as interviews DO NOT possess these properties. We have no way of knowing whether they are valid or reliable and are therefore much less predictive of a candidate’s behaviour.
Normative Measures
Psychometric tests usually compare a person’s performance on the test against a large group of people who did the test during the process of test development, called the norm group. By comparing a candidate’s performance on a test to the norm group, we can say with a high level of confidence that his performance is below average, average or above average compared to the norm group
In order to understand how this works, we need to explain the difference between what are termed “Raw Scores” and “Standard Scores
Raw Scores and Standard Scores
A raw score is the score that a person achieved out of the number of items that the test consisted of. For example, if a person achieved 20 correct answers out a total of 30 test items, his score of 20 would be his raw score
We have no way of knowing whether 20 is a below average, average or above average score. However, when we compare it to the norm group, this becomes possible. When compared to a norm group, the RAW SCORE is converted into a STANDARD SCORE, using a NORM TABLE provided by the test developer
The standard score works either on a scale from 1 – 9 (called a stanine) or 1 – 10 (called a sten)
Stanines from 1 -4 are considered below average compared to the norm group Stanines of 5 and 6 are considered to be average compared to the norm group Stanines of 7 – 9 are considered to be above average compared to the norm group.
Where does the Norm Table come from?
The Test Developer. Test developers will often research their tests on large samples of many different groups sharing common characteristics.
For instance, they could all be managers, or people with a tertiary education, or people with matric, or technical workers, or sales staff, or MBA students and so on. The test developer will therefore provide the psychologist with many different norm tables, and the psychologist would select the most appropriate one to use in each selection scenario.
Illustration
Simon has applied for a production manager position. One of the psychometric tests he did was a cognitive test which tested his General Mental Ability (GMA). GMA is an excellent overall indicator of cognitive or problem-solving capability.
The test consisted of 30 items or problems that Simon was required to solve. Simon managed to get 26 out of the 30 items correct. This is his RAW SCORE. Simon’s raw score of 26 was then compared to how well a large sample of managers did on the same test. The performance of these managers is shown in the table below. This is the NORM TABLE supplied by the test developer who compiled it in the process of developing the GMA.
Percentiles
Standard scores can also be linked to something called percentiles. You can think of a percentile as an indication of where a person ranks against the norm group. This can be very useful as we will see. Percentiles are expressed as a % So how do they work? Percentiles Explained
Getting back to Simon
Remember that Simon’s performance of 26 (raw score) correct out of 30 items converted to a stanine of 7 (standard score) when compared to the Manager Norm Group. As a percentile, this stanine of 7 would place Simon at the 89th percentile, meaning that his GMA is better than 88% of other managers.
No doubt Simon is quite an impressive candidate with respect to General Mental Ability However, if Simon had achieved a stanine of 4, it would mean that his GMA is only better than 39% of other managers, but worse than 59%. Most managers would have better GMA than Simon and would be expected to out – perform him on problem solving tasks.
Therefore;
Because psychometrics uses normative metrics, expressed as stanines (a score between 1 and 9) or stens (expressed as a score between 1 and 10). We can confidently know whether that psychological capability is below average, average or above average compared to the norm group. This helps us to understand whether a candidate is weak, average or strong with respect to the psychological capabilities required by a job. This is vital, because psychological capabilities play such a key role in determining individual job performance.
Legal Considerations
It is important to know that there are two sets of laws that govern the assessment of what we term Capability in a job selection context:
⦁ The Employment Equity Act ⦁ The Health Professions Act of 1974
According to the Health Professions Act of 1974, it is a criminal offence for persons who are not registered with the Health Professions Council of South Africa (HPCSA) as psychology practitioners, to perform psychological acts.
A psychological act is performed when any of the following are assessed:
A psychological act is also performed when a person interprets assessment results or gives feedback on those results.
According to the Employment Equity Act, all instruments used to assess psychological constructs (Capability) in an employment context must be able to demonstrate that they are:
⦁ Reliable and ⦁ Valid
Of all the assessment instruments available – whether interviews, work sample tests and so on – only psychometric tests can meet the standards of reliability and validity.
In a nutshell these 2 Acts means that only suitably qualified psychology professionals who are registered with the Health Professions Council of South Africa may decide on a test battery, administer psychometric tests, control their use, interpret test results and give feedback to any party on the results of a psychometric assessment. It also the professional responsibility of this professional to ensure that tests that are administered are valid and reliable and do not discriminate unfairly against any individual.
Key Ethical Considerations
Some of the most important ethical considerations when using psychometric tests in an organisational context are the following:
Informed Consent
This means that candidates must give their consent for test results to be used for a stated purpose, for instance in determining his suitability for a particular job.. Test results may then only be used for the stated purpose to which the candidate or employee agreed to AND MAY NOT be used for any purpose other than the stated one. For instance using this candidate’s results to determine if he is suitable for a different job that he applies for or is considered for later.
Confidentiality
Psychometric test results may not be shared with anyone that the candidate or employee has not agreed to.
Storage
Normally, the senior HR Manager in an organisation is made the custodian of assessment reports and are under obligation to store them securely where unauthorised individuals cannot have access to them.
Uninterpreted Psychometric Test Results
It is unethical and illegal for any individual who is not trained in psychometrics to attempt to interpret test results. HR and Line Manager should never attempt to interpret a psychometric test.
Feedback
Candidates are entitled to feedback. However, candidate feedback is a sensitive manner and may only be given by a trained psychology professional, registered in the correct categories with the Health Professions Council.
Candidate's rights
A candidate may refuse to participate in an assessment or give his consent for his assessment results to be released to the company. In such cases, the likely consequences of such refusal must be explained to a candidate. A candidate may also withdraw his consent for access to his assessment results. If a report has already been sent to a client, all copies of this report must be destroyed.
Poppi Act
With the advent of the Poppi Act EXTRA care should be taken to safe - keep candidate's reports, not disseminate them to others (only HR to have a copy) and to ensure that the principles of confidentiality and informed consent are strictly adhered to.
It is important to note that many of these ethical considerations are underpinned by a legal framework and also carry stiff penalties if they are contravened.
