SEHS D.2

What is the purpose of a control group in an experiment?

Participants similar to the treatment group but receiving no intervention. Provides a baseline to compare, affirming if changes are due to treatment.

Why are randomised groups important in experimental design?

Assigns participants to conditions by chance, ensuring initial group similarity, minimizing bias, and distributing confounding variables evenly.

Explain 'blinding' in experimental design.

Keeps participants unaware if they receive real or fake treatment. Prevents expectations (placebo effect) from influencing results, enhancing objectivity.

What is a double-blind experiment?

Neither participants nor researchers know who is in the treatment or control group. Eliminates bias from both sides for unbiased observation and results.

What is a placebo and how is it used?

An inert, fake treatment given to participants. Differentiates genuine treatment effects from belief or expectation (placebo effect).

Why is it important to select the best method of experimental design?

Crucial for obtaining accurate, reliable, and valid results. Minimizes bias, controls variables, and ensures findings genuinely reflect the studied variable.

What are the pros of using a placebo as a control group?

Pros:

• Accounts for mental and physical 'belief' effects.
• Confirms if treatment truly works beyond expectations.

What are the cons of using a placebo as a control group?

Cons:

• Time-consuming to create convincing fake.
• Can raise ethical issues, especially for those needing actual medical care.

What are the pros of using a 'no treatment' control group?

Pros:

• Simple and avoids ethical deception.
• Saves time and resources.
• Provides clear baseline data without intervention.

What are the cons of using a 'no treatment' control group?

Cons:

• Harder to distinguish true treatment effects (doesn't account for placebo effect).
• Limits blinding, potentially introducing bias.

Define accuracy in the context of fitness testing.

How close a measurement is to the true value. High levels ensure results correctly reflect reality, vital for valid conclusions.

Define reliability in the context of fitness testing.

Measurement consistently yields similar results when repeated under identical conditions, indicating dependable functioning.

Define precision in the context of fitness testing.

How closely repeated measurements are to each other, irrespective of their closeness to the true value.

Define validity in the context of fitness testing.

Measurement genuinely assesses what it claims to measure, ensuring the test appropriately answers the intended question.

Outline the methodology for a 30-meter sprint test, ensuring precision, accuracy, and validity.

1. Environment: Flat, dry surface.
2. Measurement: Calibrated tape for 30m track (accuracy).
3. Timing: Electronic gates at start/finish (precision).
4. Warm-up: Standardized protocol.
5. Start: Consistent standing position.
6. Execution: Tester countdown, sprint maximally; timer starts/stops via gates.
7. Repetitions & Rest: Repeat 2 more times, 3 min rest (reliability).
8. Cool-down: To aid recovery (validity focus).

Explain the difference between a null hypothesis and an alternative hypothesis.

• Null Hypothesis (H\*0): States no statistically significant difference or relationship between variables.
• Alternative Hypothesis (H\1 or H\A): States there \is\ a significant difference or relationship, which the researcher aims to prove.

Develop an alternative hypothesis for the topic 'Effect of sleep on endurance'.

Consistently sleeping more than 8 hours per night significantly improves endurance, as adequate sleep enhances recovery, energy, and muscle repair.

Develop a null hypothesis for the topic 'Effect of sleep on endurance'.

No statistically significant difference in endurance between individuals consistently sleeping more than 8 hours per night and those sleeping less.