Data collection method Strengths Weaknesses
Tests Can see results as they
happen
Time consuming / not cost
effective
Questionnaires (surveys) Easy to complete Generic / not reliable
Interviews All questions are
answered / to the point
Can be expensive /
questions may be to
personal
Focus groups People can build on each
other’s responses
Some people may not feel
comfortable in saying their
opinion in front of a group
Observation Can see exactly what is
happening
relies on the interpretation
of observation / not cost
effective
Secondary data Doesn’t cost as much to
do / someone else has
already collected the data
It may not answer the
specific questions you
need / has no control over
what is contained in the
data
