with basic, raw numerical or mathematical ability. A very precise act of computation (for instance subtraction or multiplication) was clearly indicated by the format of the question. All you had to do was carry out the calculation.
With the power questions, it was not indicated which specific mathematical computation (for instance, addition or division) had to be carried out in order to reach a solution. The task you faced was to apply a more general problem solving approach – the problem being not ‘what is the answer?’ but ‘what do I have to do to work out how to reach the answer?’
Once you have established how to reach the answer, the final task itself is often a very simple process of mathematical calculation.
Brian is 1,692 cm tall
a) true
b) false
c) can’t tell
If William is 1,680 cm tall, Kate is 2 cm taller than William, and Brian is 6 cm taller than Kate then the answer must be:
1,680 cm + 2 cm + 6 cm = 1,688 cm.
So the statement that Brian is 1692 cm tall is false.
Notice how simple the mathematics was once we had worked out what to do. This is a good example of numerical reasoning ability or aptitude, rather than just straightforward numerical ability or aptitude. Furthermore, because the information is presented verbally, this is also a reasonable example of what verbal reasoning test items may look like. Power tests are more commonly found in the numerical and verbal domains but can also crop up in the mechanical, abstract and perceptual ability areas.
OTHER TYPES OF TEST
The other two commonest types of test are Work Samples and Job Simulations, although at first glance they do not look as we imagine tests to be.
A Work Sample test is exactly what its name implies – a sample of the work the candidate is required to do. These tend to be used widely in mechanical or practical areas of work. A common example is a typing test where the candidate has to type out some hand-written notes without making any errors within a given period of time. Another example is a fork-lift truck driver moving a set number of pallets from one place to another to within a certain degree of accuracy. If you are invited for a Work Sample test, the chances are you already have some skill in the area to begin with.
Job Simulations look similar to Work Samples and the two are often confused. However, whereas a Work Sample actually involves doing a sample of the activities carried out in the target job, a Job Simulation only simulates those activities involved in the target job.
If our fork-lift truck driver was inexperienced, it would clearly not be wise to put him or her into a fork-lift truck and see how little damage is done! It would be better to measure those abilities we know are involved in driving a fork-lift truck, such as hand to eye co-ordination, spatial awareness and so on, and then use the information obtained to infer how the person might perform in the job once they had been trained. Because of this, Job Simulations are often used when selecting people for training or when they have no direct experience in or specific knowledge of the job in question.
Another common type of Job Simulation is the so-called ‘In-basket’, or ‘In-tray’, which is used for many management-based selection activities. The In-tray simply involves taking the contents of a manager’s typical in-tray and working through them, making decisions as to what to do with each item as you go. These simulations are often used to assess organizational and decision-making ability, and are quite commonly used in management selection. However, you do need the contents of a real in-tray to base the exercise on and these contents can be both numerous and diverse – an entire in-basket could easily fill this book!
In addition, tests like In-trays are very difficult to score correctly because there is often no single correct way to deal with the items. Consequently, they tend to be followed up by a presentation from, or interview with, the candidate during which they explain how they worked their way through the in-tray, what criteria they used for decision making and how they justified their actions.
HOW AND WHY COMPANIES USE APTITUDE TESTS
Where Do Tests Fit into the Wider Selection Process?
The purpose of a selection system is to make a prediction about who will be successful at the job. It does this by gathering evidence about a candidate, weighing that evidence and then making a decision as to whether or not to offer them a position.
One thing that many candidates mistakenly believe is that the test constitutes the complete selection process. In fact, tests are very rarely used as a first stage in selection. Usually, the process begins long before a job is advertised and typically it involves the following steps.
Job Analysis
This is carried out to determine the key tasks of the job. It can involve sophisticated analytical methods using data about several hundred job holders, or it can be done using ‘expert analysis’ which involves a group of individuals, who are very familiar with the job, sitting down and agreeing what the job involves. In cases where there are relatively few employees (which rules out large-scale statistical analysis) the latter method tends to be used.
Producing the Job Description
This is a formal description of the tasks identified as a result of the job analysis.
Producing the Person Specification
This often takes quite a lot of work. The key challenge for the organization here is to identify the knowledge, skills, attributes and abilities a person must possess if they are to be able to carry out the tasks described in the Job Description. Very often these characteristics, contained in the Person Specification, are classified as being either ‘essential’ or ‘desirable’.
Identifying What the Success Criteria Will Be
This involves setting success criteria for future work performance for use in work appraisals. This stage is often overlooked, but it remains an important part of the process since it allows the organization to analyze how well their selection system and selection tools actually predicted work success.
Choosing the Selection Tools
The selection tools are then chosen based on their effectiveness at measuring those characteristics described in the Person Specification. They may include interviews, tests, CVs, application forms, and individual or group exercises.
Applying the Chosen Selection Tools
This is often done in several stages, with successful candidates at one stage being invited to participate in the next. Sometimes, candidates may be pre-selected based on qualifications or experience, and then invited to come along to an assessment day (sometimes known as an assessment centre), during which all of the tools are used.
