Thurstone Scale Survey to Measure Attitudes
The Thurstone Scale was designed to measure attitudes towards an object. This tool provides high-precision measurement of the respondent’s attitude towards a complex ambiguous object, when it cannot be measured directly.
Definition of Thurstone Scale
The main principle of the scale is as follows: the respondent is asked to rate a number of statements, each having a certain value. Values are assigned depending on how clearly the attitude in question is pronounced in the statement. The final score is calculated as the mean of the values of the statements that the respondent has agreed with.
Thurstone Scale allows you to rank both statements and respondents in terms of their attitude towards the object from extremely negative to extremely favorable. Thus, the final scores of both the statement and the respondent reflect their attitude towards the object.
How to create Thurstone Survey
Stage 1. Statement Formation and Selection
The scale development starts with the formation of a wide range of statements that express the attitude relevant to the researcher. Statements can be taken from literature, personal experience, experience of those having the issue, potential respondents, or during group discussions. If possible, statements should evenly cover the entire continuum, ranging from extremely negative to extremely positive ones.
The number of statements may vary from several tens to several hundreds, and depends on the object homogeneity: the less homogeneous it is, the more statements you need and vice versa. Researchers prefer working with 20–50 judgments for convenience.
Example of Statements for Thurstone Scale Survey
- Work should not bring money instead of satisfaction.
- Promotion does not contribute to maintaining friendship with colleagues.
- If the employee believes that the manager’s order could harm the process, the employee must warn the manager about it.
Make sure to select those statements that the majority would place in the same category. If the scores are too different, the final score becomes meaningless, for the final score is the experts’ mean score.
The full list shall contain only the statements that meet the following criteria:
- Relevant to the attitude in question;
- Clear in meaning and unambiguous;
- Contain opinions and judgments rather than facts;
- Relevant to the present and not the past;
- Brief and concise;
- Reflect only the current attitude towards the object and do not touch upon the past attitude;
- Phrased as an affirmative sentence;
- Phrased in a way that one may accept or reject them;
- Phrased in a way that the respondents with either a positive or negative attitude towards the object may accept them;
- Phrased in a way that allows to get a range of opinions.
After that, the remaining statements are written down on separate cards with serial numbers.
Stage 2. Expert Assessment
At the next stage, the experts lay out cards with statements sorted by categories, from extremely negative to extremely positive. The final set of statements should allow each respondent to find a judgment he/she agrees with. Therefore, statements should be different: negative, neutral, and positive as regards the attitude in question.
The experts are typical representatives of the target audience. You may also involve those who took part in the statements formation. The more experts take part in ranking, the better. As a rule, these are 30–50 people. And the assessment of the expert majority is always taken as final, even if it contradicts the researcher’s opinion.
The expert gets a deck of cards with statements that should be split into 7–9–11 groups, depending on the scale design. Thurstone showed through experiments that the optimal number of groups is 11.
When laying out the cards, the experts should not express their agreement or disagreement with the proposed opinion. Their task is to rank the cards by the statement meaning, writing the corresponding number on the back of each card. They do not need to divide all cards equally in each cell. What matters most is the equal semantic assessment distance between the groups.
Statements can be divided into 11 groups as follows:
- Place statement with the most positive assessment of the object in the first cell.
- Place statement with the neutral assessment of the object in the sixth cell.
- Place statement with the most negative assessment of the object in the eleventh cell.
- The remaining cards shall be divided between them considering the attitude towards the object.
Stage 3. Assigning Scores to Statements
At this stage, the following is determined:
- score of each statement on an 11-point scale (median value);
- consistency of expert assessments (interquartile range).
For each statement, the number of experts who put it into one category or another is counted, as well as the relative and cumulative frequencies. Based on these data, the median value (final statement score) and the interquartile range (expert consensus) are calculated.
Stage 4. Statement Selection and Scale Building
The first statement is the one with a median value approximately equal to one and the smallest quartile range, since the smaller the quartile range, the more reliable the assessment. Then, statements with a median value of about 2 are selected, and so on, up to 11.
During the statement selection, it could be that there is only one statement with a wide quartile range in the cell. In this case, you should find out why there is only one controversial statement in the cell, that the experts could not interpret unambiguously.
Statement should evenly cover all scale points. The final scale may include 15 to 30 judgments, with each having an assigned value.
How to use Thurstone Scale to Measure Attitudes
As a result, researchers get a handy scale for measuring the characteristics they are interested in. The survey respondents are given a number of statements and asked to choose the ones they agree with. Based on scores of selected statements, you can calculate the mean value which will indicate the respondent’s attitude towards the object.
An Example of the Thurstone Scale Questionnaire
|The interests of the top management and the staff do not coincide in the majority of cases||Agree||Disagree|
|A manager should not discuss his/her personal problems with subordinates as it undermines his/her authority||Agree||Disagree|
|When a manager keeps subordinates at arm’s length, they perform their tasks more diligently||Agree||Disagree|
|In order to be an effective manager, you should be aware of your subordinates’ problems||Agree||Disagree|
|The company must fulfill its obligations towards the staff despite financial difficulties||Agree||Disagree|
|An employee’s salary should be based on the financial situation of his/her family||Agree||Disagree|
|One company employee should not receive a salary 10x bigger than that of his/her colleagues||Agree||Disagree|
|Promotions are dictated primarily by the management’s feelings towards you, rather than your professionalism||Agree||Disagree|
|Diligent performance of your job duties is a necessary and sufficient condition for your promotion||Agree||Disagree|
|It is okay for a manager to accommodate a request from a good employee in breach of the general rules||Agree||Disagree|
|A close-knit team is nice to work in, but hard to manage||Agree||Disagree|