A Step-by-step Example of Sampling
A Step-by-step Example of Sampling
The study
A Grade 5 English teacher tests a daily ten-minute vocabulary game on students with lower vocabulary scores.
Population
All 105 Grade 5 students in her school across three sections.
Sample
Twelve weak-vocabulary students from her own section, chosen by purposive sampling.
Why small and purposive
The question is about students with lower vocabulary scores, not all Grade 5 students. Twelve students studied carefully for six weeks gives enough evidence.
A Step-by-step Example of Sampling
A teacher of Grade 5 English wants to study how a daily ten-minute vocabulary game affects vocabulary retention among her students with lower vocabulary scores.
Population
All Grade 5 students in her school. Three sections, total 105 students.
Sample
She does not want to study all 105. Her question is about students with lower vocabulary scores specifically. She uses purposive sampling: twelve students across her own section, identified as scoring below 50 percent on the last vocabulary test.
Why not random
She is not trying to generalize to all Grade 5 students. She wants to know if the game helps these specific students. A random sample would dilute her focus.
Why not all 40 students in her section
Students already scoring high are not the target group for this question. Including them would muddy the data and waste her time.
Sample size
Twelve students, studied carefully for six weeks, with weekly quizzes, observation notes, and short interviews. That is enough.
This is a textbook action research sample: purposive, small, deep.
A second card that recaps the same example in a single line for quick recall.
