The Technical Quality of a Test — Part 1

quality habit

We want our tests to be good measures of student achievement so we need to pay attention to what one source calls the “technical quality of a test.”

To help me understand what quality really means, I found these definitions useful:

  1. The characteristics of a product or service that bear on its ability to satisfy stated or implied needs; “conformance to requirements”
  2. A product or service free of deficiencies; “fitness for use”

(from http://asq.org/glossary/q.html)

So what criteria should we use to improve quality?

     Source: http://www.k-state.edu/ksde/alp/resources/Handout-Module6.pdf

Criteria for establishing the technical quality of a test

  1. Cognitive complexity

The test questions will focus on appropriate intellectual activity ranging from simple recall of facts to problem solving, critical thinking, and reasoning.

Bloom’s Taxonomy*

  1. Content quality

The test questions will permit students to demonstrate their knowledge of challenging and important subject matter.  The emphasis of the test should be a reflection of the emphasis of the lecture.

  1. Meaningfulness

The test questions will be worth students’ time and students will recognize and understand their value.

  1. Language appropriateness

The language demands will be clear and appropriate to the assessment tasks and to students.  It should reflect the language used in the classroom.  Test items should be stated in simple, clear language, free of nonfunctional material and extraneous clues, and free of race, ethnic, and sex bias.

  1. Transfer and generalizability

Successful performance on the test will allow valid generalizations about achievement to be made.

  1. Fairness

Student performance will be measured in a way that does not give advantage to factors irrelevant to school learning:  scoring schemes will be similarly equitable.

Basic rules of fairness:

  • Test questions should reflect the objectives of the unit
  • Expectations should be clearly known by the students
  • Each test item should present a clearly formulated task
  • One item should not aide in answering another
  • Ample time for test completion should be allowed
  • Assignment of points should be determined before the test is administered.
  1. Reliability

Answers to test questions will be consistently trusted to represent what students know.

 

*More on Bloom’s Taxonomy in a future post.

Let’s examine this list in detail.

  1. Cognitive complexity

Oh, I like this one.  We should be challenging our students with intellectual activity; more importantly with a range of it.  This brings me back to the previous post (below) where we discussed the classification of questions based on how easily they can be answered; from those that most can get to the few “A-B Breakers”.  There should be some questions that make the student think, “Hmmm, how can I use what I have learned to answer this?” and some that bring on the reaction of “Oh yes, I have seen all this before and I can remember it.”

I recall a question on a botany exam that asked me to imagine holding a plant stem in my hand and piercing it with a straight pin.  I needed to describe the various tissue types the pin might touch as it passed through to the middle of the stem.  I had learned the list of tissues already; this question forced me to consider their locations in the plant and organize them from the outside to the inside.  I hadn’t already considered that idea so I was cognitively challenged but I had all the tools I needed to answer the question.

One message that comes across in a number of the sources is that we can be tempted to test on the easier parts of the material rather than the important parts.  Considering cognitive complexity helps us focus on drawing from our students what they have learned beyond simple recall.

  1. Content Quality

Again, we need to ensure we are testing more than simple recall but we also have to make sure we are not writing questions that test outside of the course material.

Here is one concern I have about emphasizing on the test what is emphasized in the lecture: if this is taken too literally, our students are at risk of paying attention only to the information we explicitly label as important and ignoring any nuances or “items of lesser importance.”  They are often keenly tuned into the way we write on the board, in a PowerPoint slide, or on digital lecture notes and are quick to infer that words in bold, italics, all capitals, or that are underlined are the only things they should study for a test.  I found I was giving them that impression in my lectures so I changed the way I wrote on the board, forcing my students to consider all the words I presented.

We will continue this discussion in the next post!