7 (1)- scientific processes (aims, hypothesis, sampling methods, bias and pilot studies)

Aim

A general statement of what a study intends to investigate; broader than a hypothesis and not directly testable.

Hypothesis

A testable statement predicting a relationship or difference between variables, allowing scientific testing.

Directional hypothesis

Predicts the expected direction of results, increasing clarity but risking bias.

Non-directional hypothesis

Predicts a difference or relationship without stating direction, reducing bias.

Population

The entire group a researcher wants to study, though usually impractical to access fully.

Sample

A subset of the population used in research, whose representativeness affects generalisability.

Random sampling

Every member has an equal chance of selection, reducing bias but often impractical.

Systematic sampling

Selecting every nth person, efficient but may introduce bias if patterns exist.

Stratified sampling

Sampling proportional to population characteristics, increasing representativeness.

Opportunity sampling

Sampling those most available, quick but highly biased.

Volunteer sampling

Participants self-select, often leading to volunteer bias.

Sampling bias

When certain groups are over- or under-represented, reducing population validity.

Pilot study

A small-scale trial run conducted before the main study to identify issues.

Aims of piloting

To refine procedures, materials, and variables, improving reliability and validity.