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Strengths and weaknesses

26 July, 2019 - 10:10
Available under Creative Commons-ShareAlike 4.0 International License. Download for free at http://cnx.org/contents/ce6c5eb6-84d3-4265-9554-84059b75221e@2.1

All types of selected response items have a number of strengths and weaknesses. True/False items are appropriate for measuring factual knowledge such as vocabulary, formulae, dates, proper names, and technical terms. They are very efficient as they use a simple structure that students can easily understand, and take little time to complete. They are also easier to construct than multiple choice and matching items. However, students have a 50 per cent probability of getting the answer correct through guessing so it can be difficult to interpret how much students know from their test scores. Examples of common problems that arise when devising true/false items are in Table 11.3.

Table 11.3 Common errors in selected response items

Type of item

Common Errors

Example

True False

The statement is not absolutely true – typically because it contains a broad generalization

T F The President of the United States is elected to that office. This is usually true but the US Vice President can succeed the President.

The item is opinion not fact

TF Education for K-12 students is improved through policies that support charter schools. Some people believe this some do not

Two ideas are included in item

TF George H Bush the 40th president of the US was defeated by William Jefferson Clinton in 1992

Irrelevant cues

T F The President of the United States is usually elected to that office. True items contain the words such as usually generally; whereas false items contain the terms such as always, all, never.

Matching

Columns do not contain homogeneous information

Directions: On the line to the US Civil War Battle write the year or confederate general in Column B.
 

Column A Column B
Ft Sumter General Stonewall Jackson
2nd Battle of Bull Run General Johnson
Ft Henry 1861
  1862

Column B is a mixture of generals and dates

Too many items in each list

Lists should be relatively short (4 - 7) in each column. More than 10 are too confusing.

Responses are not in logical order

In the example with Spanish and English words should be in a logical order (they are alphabetical). If the order is not logical, student spend too much time searching for the correct answer.

Multiple Choice

Problem (i.e. the stem) is not clearly stated problem

New Zealand

  • Is the worlds' smallest continent
  • Is home to the kangaroo
  • Was settled mainly by colonists from Great Britain
  • Is a dictatorship

This is really a series of true-false items. Because the correct answer is c) a better version with the problem in the stem is

  • Much of New Zealand was settled by colonists from
  • Great Britain
  • Spain
  • France
  • Holland
 

Some of the alternatives are not plausible

Who is best known for their work on the development of the morality of justice.

  • Gerald Ford
  • Vygotsky
  • Maslow
  • Kohlberg

Obviously Gerald Ford is not a plausible alternative

 

Irrelevant cues

  • Correct alternative is longer
  • Incorrect alternatives are not grammatically correct with the stem
  • Too many correct alternatives are in position “b” or
  • making it easier for students to guess. All the options (e.g. a, b, c, d) should be used in approximately equal frequently (not exact as that also provides clues).
 

Use of “All of above”

  • If “all of the above” is used then the other items must be correct. This means that a student may read the 1st response, mark it correct and move on. Alternatively, a student may read the 1st two items and seeing they are true does nor need to read the other alternatives to know to circle “all of the above”. The teacher probably does not want either of these options.
 

In matching items, two parallel columns containing terms, phrases, symbols, or numbers are presented and the student is asked to match the items in the first column with those in the second column. Typically there are more items in the second column to make the task more difficult and to ensure that if a student makes one error they do not have to make another. Matching items most often are used to measure lower level knowledge such as persons and their achievements, dates and historical events, terms and definitions, symbols and concepts, plants or animals and classifications (Linn & Miller, 2005). An example with Spanish language words and their English equivalents is below:

Directions: On the line to the left of the Spanish word in Column A, write the letter of the English word in Column B that has the same meaning.

Column A

Column B

  1. ___ Case

A. Aunt

  1. ___ Bebe

B. Baby

  1. ___ Gata

C. Brother

  1. ___ Perro

D. Cat

  1. ___ Hermano

E. Dog

 

F. Father

 

G. House

 

While matching items may seem easy to devise it is hard to create homogenous lists. Other problems with matching items and suggested remedies are in Table 11.3.

Multiple Choice items are the most commonly used type of objective test items because they have a number of advantages over other objective test items. Most importantly they can be adapted to assess higher levels thinking such as application as well as lower level factual knowledge. The first example below assesses knowledge of a specific fact whereas the second example assesses application of knowledge. Who is best known for their work on the development of the morality of justice?

  1. Erikson
  2. Vygotsky
  3. Maslow
  4. Kohlberg

Which one of the following best illustrates the law of diminishing returns

  1. A factory doubled its labor force and increased production by 50 per cent
  2. The demand for an electronic product increased faster than the supply of the product
  3. The population of a country increased faster than agricultural self sufficiency
  4. A machine decreased in efficacy as its parts became worn out

(Adapted from Linn and Miller 2005, p, 193).

There are several other advantages of multiple choice items. Students have to recognize the correct answer not just know the incorrect answer as they do in true/false items. Also, the opportunity for guessing is reduced because four or five alternatives are usually provided whereas in true/false items students only have to choose between two choices. Also, multiple choice items do not need homogeneous material as matching items do.

However, creating good multiple choice test items is difficult and students (maybe including you) often become frustrated when taking a test with poor multiple choice items. Three steps have to be considered when constructing a multiple choice item: formulating a clearly stated problem, identifying plausible alternatives, and removing irrelevant clues to the answer. Common problems in each of these steps are summarized.