Term Definition
Mean Square Error

The total error of a survey estimate; specifically, the sum of the variance and the bias squared.

Synonyms - mean square error (MSE), mean square error
Measurement equivalence
Equivalence of the calibration system used in the questionnaire and the translation.
Measurement error
Survey error (variance and bias) due to the measurement process; that is, error introduced by the survey instrument, the interviewer, or the respondent.
Metadata

Information that describes data. The term encompasses a broad spectrum of information about the survey, from study title to sample design, details such as interviewer briefing notes, contextual data and/or information such as legal regulations, customs, and economic indicators. Note that the term ‘data’ is used here in a technical definition. Typically metadata are descriptive information and data are the numerical values described.

Microdata
Nonaggregated data that concern individual records for sampled units, such as households, respondents, organizations, administrators, schools, classrooms, students, etc. Microdata may come from auxiliary sources (e.g., census or geographical data) as well as surveys. They are contrasted with macrodata, such as variable means and frequencies, gained through the aggregation of microdata.
Minority country

A country with high per capita income (the minority of countries).

Synonyms - minority countries
Mode

Method of data collection.

Synonyms - modes, mode(s)
Mouse clicks

“Mouse click files record each action the respondent or interviewer takes using the computer’s mouse, ranging from the presence or absence of simple single mouse clicks to the position of the mouse cursor at a specified time interval on an x − y coordinate of the survey page” (Olson & Parkhurst, 2013).

Multi-Trait-Multi-Method (MTMM)

A technique that uses the correlations between multiple methods (i.e. modes) and multiple traits (i.e. variables) to assess the validity of a measurement process. 

Synonyms - multi-trait multi-method, MTMM, MTMM studies, Multi-trait-multi-method