Designing a study · Conception d'une étude
| English | Français |
|---|---|
| hypothesis/haɪˈpɒθəsɪs/ | hypothèse |
| null hypothesis/nʌl haɪˈpɒθəsɪs/ | hypothèse nulle |
| independent groups/ˌɪndɪˈpendənt ɡruːps/ | groupes indépendants |
| repeated measures/rɪˈpiːtɪd ˈmeʒəz/ | mesures répétées |
| random allocation/ˈrændəm ˌæləˈkeɪʃn/ | allocation aléatoire |
| extraneous variable/ekˈstreɪnɪəs ˈveərɪəbl/ | variable extrinsèque |
A correlation leaves several explanations open
- Students who report more sleep also report higher grades. Sleep may matter, but study habits or worry could also contribute to the association.
- State the hypothesis and · et null hypothesis 零假设 before the planned analysis. A null result should be reported with the method and uncertainty, not hidden.
Your study finds no effect. What should you do? · Votre étude ne trouve aucun effet. Que devriez-vous faire ?
Report the method, findings and uncertainty honestly. No detected effect does not prove the true effect is exactly zero.
Choose the design for the question
- Independent groups 组间设计 use different people; repeated measures 组内设计 use the same people across conditions. Consider feasibility, individual differences and carryover.
- Random allocation 随机分配 helps balance groups. Counterbalancing helps with order effects. Neither guarantees removal of all differences or makes an unsuitable method suitable.
Match each design to the safeguard it needs. · Reliez chaque conception à la sauvegarde dont elle a besoin.
Different people may differ to begin with; the same people carry practice and fatigue across. · Des personnes différentes peuvent différer dès le départ ; les mêmes personnes apportent pratique et fatigue aux sessions suivantes.
Separate an extra influence from a confound
- An extraneous variable 无关变量 may influence the outcome. It becomes a confound when it varies systematically with the condition and offers an alternative explanation.
- Different testing times are a possible concern; check whether time is linked to condition. Record controls and remaining limitations instead of silently excluding inconvenient data.
You could not control the time of day participants were tested. What should you do? · Vous n'avez pas pu contrôler l'heure de la journée à laquelle les participants étaient testés. Que devriez-vous faire ?
Report testing-time variation and whether it was linked to condition. An extra variable is a confound when it varies systematically with the condition.
Name one extraneous variable in a study of music and memory, and say how you would control it. · Nommez une variable extrinsèque dans une étude sur la musique et la mémoire, et dites comment vous la contrôleriez.
Example: test conditions at comparable times and record sleep-related limitations. A common time alone does not guarantee identical tiredness.
Plan the report before seeing the answer
- Define the measure, analysis and ethical safeguards. Exploratory changes can be useful, but label them as exploratory and explain why they were made.
- No detected effect does not prove the true effect is exactly zero. Consider sample size, measurement and uncertainty rather than promising a score for a particular result.
More sleep goes with better grades. Which explanations remain possible? Choose all that apply. · Plus de sommeil va de pair avec de meilleures notes. Quelles explications restent possibles ? Choisissez toutes celles qui s'appliquent.
Three live explanations, and the correlation alone cannot separate them. · Trois explications viables, et la corrélation seule ne peut pas les distinguer.
Music is always tested in the morning and silence in the evening. Why is this a concern?
Testing time supplies an alternative explanation. The concern does not establish that the result is false or which factor actually caused it.
Check a transfer design
- If music participants are tested in the morning and silence participants in the evening, time and music are entangled. A time-of-day difference can compete with the music explanation.
- A fairer allocation and comparable procedure address that problem. Correlation alone cannot separate direction of effect and third-variable accounts.
A fairer allocation and comparable procedure address that problem. Correlation alone cannot separate direction of effect and third-variable accounts.