Designing a study · Diseñando un estudio
| English | Español |
|---|---|
| hypothesis/haɪˈpɒθəsɪs/ | hipótesis |
| null hypothesis/nʌl haɪˈpɒθəsɪs/ | hipótesis nula |
| independent groups/ˌɪndɪˈpendənt ɡruːps/ | grupos independientes |
| repeated measures/rɪˈpiːtɪd ˈmeʒəz/ | medidas repetidas |
| random allocation/ˈrændəm ˌæləˈkeɪʃn/ | asignación aleatoria |
| extraneous variable/ekˈstreɪnɪəs ˈveərɪəbl/ | variable extraña |
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 · y 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? · Su estudio no encuentra efecto. ¿Qué debería hacer?
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. · Asocie cada diseño con la salvaguarda que necesita.
Different people may differ to begin with; the same people carry practice and fatigue across. · Las personas pueden diferir desde el principio; las mismas personas portan práctica y fatiga a través de los tiempos.
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? · No pudo controlar la hora del día en que se probó a los participantes. ¿Qué debería hacer?
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. · Nombre una variable extraña en un estudio sobre música y memoria, y diga cómo la controlaría.
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. · Más sueño va acompañado de mejores calificaciones. ¿Cuáles explicaciones siguen siendo posibles? Elija todas las que correspondan.
Three live explanations, and the correlation alone cannot separate them. · Existen tres explicaciones viables, y la correlación sola no puede separarlas.
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.