Is the new delivery service any good?
A pizza chain starts a faster delivery service. The manager says, "It works." A courier says, "It is a mess." Both feel sure.
You can ask people, count minutes, compare with other shops, or check with a second source. Each is a way to evaluate.
Key words
| Word | What it means |
|---|---|
| Qualitative | about opinions, feelings and reasons, shown in words |
| Quantitative | about numbers and counts |
| Experiment | a test in which you change one thing and watch the result |
| Survey | the same questions asked of many people |
| Benchmarking | comparing your result with a standard or with the best others |
| Corroboration | checking a claim against another source; also called cross-referencing |
| Triangulation | using three or more different methods or sources to check one finding |
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By the end of this lesson
Note
I can name five evaluation techniques, say what each is for and choose one to fit a question.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Five evaluation techniques
| Technique | What it is | Data-work example |
|---|---|---|
| Qualitative | Interviews, observations, workshops: findings in words | Ask five couriers what slows them down |
| Quantitative | Experiments, surveys, statistical analysis: findings in numbers | Average delivery minutes for each shop |
| Benchmarking | Compare with a standard or the best others | Is each shop slower than the chain average? |
| Corroboration | A second source agrees with the first | The app log and the couriers' notes give the same story |
| Triangulation | Three or more different methods agree | Interviews, timings and customer complaints all point one way |
The cells students fill in are left blank in this preview.
Words and numbers
Qualitative methods find out why. In an interview, observation or workshop, people explain in their own words. You get depth but few people.
Quantitative methods count how much. An experiment changes one thing. A survey asks many people the same questions. Statistical analysis works out averages and spreads.
Run it: a quantitative look
select shop, count(*) as deliveries,
avg(minutes) as average_minutes,
min(minutes) as fastest, max(minutes) as slowest
from deliveries
group by shop
order by shop;Benchmarking
Benchmarking compares a result with a standard. The standard may be the chain average, a target, or the best other shop.
A result of 43 minutes means little alone. Next to a chain average of 34 minutes, it means the shop is slow.