• tool for measuring attitudes and orientations in a large population
• best method available to collect original data for
describing a population too large to observe directly
• Respondents – those who participate in surveys – they
must be competent and willing to answer
2 types of sampling methods
Non-probability sampling – for obtaining information
about specific groups
• > available subjects
• > purposive/judgemental sampling
• > snowball sampling
• > quota sampling – in cells
Probability sampling
• primary method of selecting large, representative
samples
• Provide useful descriptions of the total population
• Sample of individuals from a population containing
essentially the same variations that exist in the population
Terms to remember
Representativeness – if the aggregate characteristics of
the sample closely approximate those same aggregate characteristics in the
population
Population – aggregation of elements from which the
sample is selected
Sample – selected element or respondent
Sampling bias – those selected are not typical or
representative of the larger population they have been chosen from
Sampling designs
Simple random sampling – assigning a number to each
element in the list
Systematic sampling – every kth element in the total
list is systematically chosen
Stratified sampling – appropriate numbers of elements
are drawn from homogenous subsets of the population
Cluster sampling – initial sampling of groups of
elements (clusters), followed by the selection of elements within each of the
selected clusters – can be multi-stage
Sampling error – the degree of error to be expected for
a given sample design
Confidence level – accuracy of our sample statistics
fall within specified interval from the parameter (e.g. 95%, 99%, 90%)
Questionnaire
• Instrument designed to elicit information useful for
analysis
• Operationalization – measurement
• > validity – what we intend to measure
• > reliability – extent to which measures give
consistent results
• Open-ended questions – respondents provide answers
• Close-ended questions – respondents elect an answer from
the list of options
Tips
• Make items clear –
“Do you agree with the peace agreement?”
• Avoid double-barreled
questions – “Do you think that K-12 will make our students globally competitive
and our education standards globally at par?”
• Make relevant
questions
• NO difficult words
• NO negative questions
– “Do you NOT agree..”
•NO questions with possibly different standards – “Do you
think that students today are liberal?”
•NO leading questions – “Due to changing times, do you
agree that government policies must adapt to the changes?”
•NO assuming questions – “How often do you go out with
your gf/bf?”
Exercises: Improve the response options
•Answers should match the questions and set of options –
“Are you satisfied with Ateneo education?” “barely,
sometimes, often, very”
•Answers should be mutually exclusive – “How often do you
study?” “everyday, everynight, every weekend, once
a week, more than once a week, monthly, never”
Designing a questionnaire
•Start with easy questions
•Place questions that are related in one block
•Design should be logical
•Introduce difficult and sensitive questions carefully
•Do not raise those in the beginning nor end
•Instructions must be clear and consistent
References:
Babbie, E. (2001). The practice of social research. Belmont, CA: Wadsworth/Thomson Learning.
Sterkens, C. (2010). Class handouts on quantitative methods. Radboud University Nijmegen
