Questionnaires and Surveys

A standardized self-report instrument

A questionnaire is a standardized self-report instrument designed to collect systematic and comparable data from large samples. It may consist of closed-ended items (Likert scales, multiple-choice) and open-ended questions, administered by post, web, phone, or in person — each mode carrying distinct coverage, cost, and bias profiles. Data quality depends directly on careful question wording, ordering, and pretesting.

Defining the Concept

A questionnaire is a written data-collection instrument consisting of predetermined, standardized questions designed to measure respondents' knowledge, attitudes, behaviors, or opinions on a given topic. By presenting identical questions in the same order to every participant, the researcher ensures comparability of responses. This standardization — unlike open-ended individual interviews — enables consistent measurement across large samples and makes the data suitable for quantitative analysis.

How It Works: Types and Administration Modes

Survey questions fall into two broad types. Closed-ended items (Likert scales, multiple-choice, ranking) offer predetermined response categories, facilitating coding and analysis. Open-ended questions allow respondents to answer in their own words, adding depth but requiring greater analytical effort. Administration modes include mail surveys (wide geographic reach, low cost, low response rate), online surveys (fast, inexpensive, but risk of digital-access bias), telephone surveys, and face-to-face administration (higher response rate, but risk of interviewer effect).

A Concrete Application Example

Suppose an educational researcher is investigating burnout levels among teachers. The researcher embeds the Maslach Burnout Inventory (MBI) — rated on a 7-point Likert scale — into an online questionnaire, adding demographic variables such as years of experience and school type. The instrument is pretested and ambiguous items are revised. A link is then emailed to 800 teachers nationwide. The resulting data are analyzed with independent-samples t-tests and multiple regression to identify organizational predictors of burnout.

Common Pitfalls and Good Practice

Common design pitfalls include double-barreled questions (asking two things in one item), leading language (wording that implies a desired answer), vague time references, and excessively long instruments. To maximize response rates, keep the questionnaire brief, include a clear cover letter, and send reminders when appropriate. Social desirability bias — the tendency to answer in socially acceptable ways — can be reduced by guaranteeing anonymity on sensitive topics. Pretesting is indispensable: piloting with a small group reveals comprehension problems and validates estimated completion time.

Key terms

Likert Scale: A rating scale in which respondents indicate their degree of agreement using 5 or 7 ordered response categories.
Closed-Ended Question: A question offering predetermined response options, making coding and comparison straightforward.
Response Rate: The proportion of contacted individuals who complete the questionnaire; critical for assessing sample representativeness.
Pretesting: Piloting the questionnaire with a small group to verify item clarity and estimate completion time.
Social Desirability Bias: Respondents' tendency to report socially acceptable answers rather than their true opinions or behaviors.