Triangulation
Triangulation
- Definition. Using more than one source, tool, or method to study the same phenomenon.
- Three types. Data (different sources), method (different tools), investigator (different observers).
- Why. Each tool has a blind spot. When three tools agree, the finding is much more likely real.
- Effect. Triangulation protects against bias and increases validity.
Triangulation
This is one of the most important ideas in action research. Learn the definition and the reasons.
What triangulation is
Triangulation is the practice of using more than one source, tool, or method to study the same phenomenon. The name comes from surveying: to find a point on a map exactly, you take readings from three different angles. In research, you confirm a finding by approaching it from different angles.
The three types
- Data triangulation. Different sources of data (students, teachers, parents, written work).
- Method triangulation. Different methods (observation, interview, test scores).
- Investigator triangulation. Different observers looking at the same data (the teacher plus a colleague).
Most action research uses method triangulation: combining observation, questionnaire, interview, and tests.
Why it matters
Every tool has a blind spot.
- Observation reflects what the teacher noticed. She did not notice the rest.
- Questionnaire reflects what students were willing to write down. Some lie. Some skip questions.
- Interview reflects what the student wanted to say in that moment. Mood matters.
- Test scores reflect performance on one task on one day. Bad sleep changes a score.
Each tool, on its own, is biased. Each tool, on its own, can mislead the teacher.
When three different tools agree, the finding gains confidence; agreement does not prove it absolutely, but it raises the chance that the result is real. When the tools disagree, the picture is more complex; that disagreement is itself useful evidence and tells the teacher to investigate further before drawing a conclusion.
A short rule
Triangulation turns one piece of evidence into a confirmed pattern.
How it strengthens validity
In research, validity is the question of whether the study actually measured what it set out to measure. A related idea is reliability: whether the same tool would give the same result on a repeat measurement under similar conditions. Triangulation directly improves validity. If the teacher concludes “the new strategy improved participation”, the conclusion is far stronger if it comes from four different sources of evidence rather than from a single quiz score.
The line to remember is short: triangulation protects against bias and increases the validity of the findings.
One more card to tie the practice back to the technical idea of validity.
