Perceptual Ability Study Guide for the DAT

General Information

This section of the Dental Admission Test (DAT) is always the second section administered. There are six categories of questions, forming six subtests with 15 questions in each one. There are 90 questions total, and the time limit is 60 minutes, averaging to 40 seconds per question. You’ll find that some of the questions will take less than 40 seconds and that others will take more time.

These six question categories are always administered in the same order on the test:

• Apertures
• View Recognition
• Angle Discrimination
• Paper Folding
• Cube Counting
• Spatial Relations/3-D Form Development

This test section assesses your ability to find small differences, a skill that predicts future success in manual dexterity, an important skill in dentistry. The questions include both two-dimensional and three-dimensional figures, and you will need to visualize a great deal to answer them.

Apertures

An aperture just means an opening or a gap in something. For this task, you must gauge whether or not a three-dimensional object can move through an opening.

The General Procedure

Given a selection of three-dimensional shapes and an opening, you will need to determine which shape can fit through the opening. The right shape can be rotated before entering the opening, but it cannot be rotated while inside the opening.

One way to determine a shape’s ability to move through an opening is by considering three of its faces: the top/bottom view, the front/back view, and the left/right side view. Upon finding these views, only consider the outline of each view’s shape. If any of these outlines (and therefore faces of the shape) can fit through a given opening, then the entire shape will be able to. An example of this is below:

If any of these views can fit through an opening, the original three-dimensional shape can also.

You will also be tasked with examining whether or not a shape will perfectly fit through an opening. This means that a shape will pass through an opening with no extraneous space remaining on any side.

It is important to note that the opposing views will be mirrors of each other. So if a shape could fit through an opening if it was mirrored vertically or horizontally, consider mentally picturing the shape from the opposite view: The opposite of the front is the back, the opposite of the top is the bottom, and the opposite of the left side is the right side. For instance, if the shape can fit through from the bottom view, but an answer choice stipulates it can fit through from the top view, that is the correct answer.

Examples

The following are example questions to help you better understand the concept.

Example 1

Will the following shape pass through the corresponding opening?

A. No, neither the top view, front view, nor side view will allow the shape to pass through the opening.
B. Yes, the top view of the object will allow the shape to pass through.
C. Yes, the front view of the object will allow the shape to pass through.
D. Yes, the side view of the object will allow the shape to pass through.

The correct answer here is B. This is because the top view of the shape is where the viewer is looking down (as if from above) onto the shape. The top view of the shape yields the following transformation:

This shape matches the opening; thus, the entire shape should be able to pass through the opening.

Example 2

Will the following shape pass through the corresponding opening?

A. No, neither the top view, front view, nor side view will allow the shape to pass through the opening.
B. Yes, the top view of the object will allow the shape to pass through.
C. Yes, the front view of the object will allow the shape to pass through.
D. Yes, the side view of the object will allow the shape to pass through.

The correct answer here is C. The orientation of the shape, viewed from the front, is as follows:

Since this is exactly the same shape as the opening, only mirrored vertically, this shape simply needs to be rotated 180° (looked at from the back view) to fit through the opening.

Now that you understand the underlying concept, here is a sample question like you’ll see on the actual test

Which opening will this shape fit through?

Answer choices:

When looking at what options are immediately available, it may not seem like our shape could pass through any of these openings. However, keep in mind that we can rotate the shape before we try to pass it through any openings. If we rotate our shape 90° counter-clockwise, the front view of it matches up perfectly with the opening in choice A. Thus, A is the answer.