This work began because in the teaching
department in which Greg lectures (at a University of Technology), they needed to have some way of predicting whether or not a
student had the potential for a career in Mechanical Engineering.
The use of existing tests was subject to
a contract and royalty payments, so Greg started from the beginning
and developed his own bank of tests. He did not believe that
conventional tests of ability in mathematics and physics were
sufficient to predict engineering aptitude.
He began by listing all the separate types of thinking that
might need to be measured, with a view to applying the test and establishing
whether or not any of the sub-tests was predictive of engineering performance.
For five semesters they correlated each student’s result
for each test with that student’s mark for the subject
‘Engineering Mechanics 1’.
Greg's initial bank of tests included all of the following:
- Knowledge of mechanical consequences (part of this test
is reproduced below, as an example)
- Freehand drawing dexterity
- Mental arithmetic
- Ability to define the meaning of given common words
- Ability to describe the steps in getting a car started
- Ability to estimate angles drawn on paper
- Ability to estimate lengths of lines drawn on paper as
well as of real objects
- Manual dexterity in hammering panel pins into wood and
marking out and cutting a hexagon from thick cardboard
- Ability to recognize and name common mechanical objects
presented to candidates
- Ability to recognize and name the materials of which common
objects are made
- Ability to estimate the mass of given objects that can
be lifted by the candidate
- Ability to estimate the volumes of each a set of varied
containers of different sizes
- Short term memory applying to numbers, words, pictures
and items displayed on a tray
- Dexterity when drawing with a pencil and ruler
- Knowledge of engineering history, processes, products
- Ability to classify given sets of words, e.g. ‘fish
peas, peanuts, beer’: these are ‘foodstuffs’
- Ability to de-code simple codes
- Vocabulary applying to geometry
- Vocabulary applying to physics
- Common sense evaluation of the logistics of undertaking
simple projects, and estimation of the time required for
- Use of prepositions
- Number of books read under different headings, in the
candidate’s life (not a test, but a self-report)
- Types and frequency of the use of tools in the candidate’s
own experience (also a self-report)
- Mathematical thinking applied to conventional mathematical
problems as encountered in high school
- Knowledge of common mathematical formulae, e.g. the area
of a circle, the volume of a sphere
- Knowledge of some of the basic properties of materials,
e.g. given a list of five materials, name the hardest one
- A survey of the depth of interest that the candidate showed
for a variety of subjects (also a self-report). The idea
here was to see if the candidate expressed an interest in
topics related to engineering, when these topics were imbedded
in a long list of many other types of topic, covering, for
example, sport, the arts, entertainment and politics.
In due course, all the tests were tested for their predictive
value, by correlating test scores with the candidates’
subsequent grades in the subject we call ‘Engineering
Mechanics 1’. Nearly all of the tests in the bank showed
a positive correlation with the subsequent grades achieved
by the students. Only four of the tests showed virtually no
correlation: these were those that investigated the amount
and type of reading that the candidates had done in their
lives, and the number and range of topics that the candidates
claimed to be interested in.
For the remaining 24 tests, the correlation coefficients
ranged from +0.27 to + 0.48. Of itself, this would not appear
to be a strong enough correlation to predict the suitability
of any individual. More reliability was obtained later, by
taking an aggregate score of the 14 most predictive tests,
and the correlation of this aggregate with the mark obtained
in ‘Engineering Mechanics 1’ was found to be +0.61.
At this level of correlation, one could definitely say that
the better the score on the entrance test, the more likely
a candidate was to do well in Mechanics 1. However, at this
time the level of predictability was still not high enough
to be able to claim that any given candidate would or would
not make it in Mechanics 1. In particular, there was the problem
that a significant number of students who scored high on this
bank of tests actually failed the subject. The researchers realized that
one cannot say that potential will always be realized: there
are always capable students who put in too little effort,
for a variety of reasons.
The merit of the test became apparent after it had been in
use for a few successive semesters, when it was observed that
candidates who had scored less than 28% overall for the bank
of tests had not managed to pass Mechanics 1, even on their
third attempt. We concluded that at the very least, this empirical
measure gave us a lower cut-off point. Candidates scoring
29% or more were found to pass the subject on their second
or third attempt. This result gave us confidence that we could
identify candidates worthy of giving extra attention, who
might eventually benefit from extended training. And we could
predict with virtually complete certainty that anyone scoring
less than the empirical 28% would not be a suitable candidate
for studying engineering.
After considerable experience, we narrowed down the size of
the bank of tests undertaken by candidates to 12, as a practical
necessity, for the sake of logistics.
If anyone is interested in the development of this research
project, or in using the tests, they are welcome to e-mail
the author at firstname.lastname@example.org
TEST OF MECHANICAL CONSEQUENCES ©
Gregory Pastoll 2005
(This is an extract from one of a bank of approx 30 different
Circle the appropriate letter in each case, e.g. a b c d
- Two pendulums: each has the same mass, but the string
lengths are different. Which one will swing faster?
a..... b..... c..... (both the same)
- A drum with two sections of different diameters is free
to turn on an axle. Attached to the drum are ropes woundin
opposite directions. One person pulls on the rope at ‘a
‘, and another at ‘b ‘.Which one will
find it easier to pull?
a..... b..... c..... (no difference)
A string is fastened to a solid beam at
A heavy collar is allowed to fall from ‘a ‘
to ‘b ‘,
where it strikes a bar tied to the string.
If the string breaks, where is it most likely to break?
a..... b..... c..... (somewhere in the middle)
- You have five small stones. All five are approximately
round and have the same density.
Which one could you throw the furthest? a..... b..... c.....
Which one could you throw the least far? a..... b..... c.....