Collecting data · Recopilar datos
| English | Español |
|---|---|
| population/ˌpɒpjʊˈleɪʃn/ | población |
| sample/ˈsæmpl/ | muestra |
| representative/ˌreprɪˈzentətɪv/ | representativa |
| qualitative data/ˈkwɒlɪteɪtɪv ˈdeɪtə/ | datos cualitativos |
| quantitative data/ˈkwɒntɪteɪtɪv ˈdeɪtə/ | datos cuantitativos |
| discrete/dɪˈskriːt/ | discreta |
| continuous/kənˈtɪnjuːəs/ | continuos |
| histogram/ˈhɪstəɡræm/ | histograma |
Define whom a finding describes
- A population 总体 is the target group; a sample 样本 is the observed subset. A class survey can describe that class without establishing a school-wide percentage.
- A suitably representative 有代表性的 sample requires attention to selection, participation and the question asked. A large voluntary response does not automatically resolve nonresponse.
Distinguish labels from measured amounts
- Qualitative data 定性数据 are categories. Quantitative data 定量数据 measure amounts; discrete · discreta 离散 data use distinct countable values, while continuous 连续 data are modelled over intervals.
- A numerical route label is still a category. Recorded continuous measurements can be rounded, so printed decimal precision alone does not decide the underlying type.
Match each variable to its data type. · Asocia cada variable con su tipo de dato.
Counted values are discrete; measured values are continuous. The type decides which chart is legitimate. · Los valores contados son discretos; los valores medidos son continuos. El tipo determina qué gráfico es legítimo.
Match the display to the data
- A histogram 直方图 uses numeric class intervals. For unequal widths, frequency density is frequency divided by width so bar area represents frequency.
- Separate category bars and label units, scale and count scope. A pie chart requires mutually exclusive parts of a defined whole; missing responses must not silently become a known category.
Which chart suits continuous data such as height? · ¿Qué gráfico se adapta a datos continuos como la altura?
A histogram displays frequencies over numeric intervals. With unequal interval widths, use frequency density so area represents frequency; an empty interval can have zero height. · Un histograma muestra frecuencias sobre intervalos numéricos. Con anchos de intervalo desiguales, usa densidad de frecuencia para que el área represente la frecuencia; un intervalo vacío puede tener altura cero.
Two sampling plans have different risks. Asking a canteen queue excludes nonusers. Selecting every tenth name can cover the full roll, but needs a random start and a check for patterns in the ordering. Neither method guarantees honest responses or removes all nonresponse; record the actual procedure and limits.
To study canteen preferences across a school, which listed selection plan best covers the full student population? · Para estudiar preferencias de cafetería en toda una escuela, ¿qué plan de selección listado cubre mejor a toda la población estudiantil?
Selection from the full roll can include nonusers. A systematic every-tenth-name plan needs a random start and a check for patterns; nonresponse remains a limitation, so it does not guarantee perfect representativeness. · La selección de la matrícula completa puede incluir no usuarios. Un plan sistemático cada décimo nombre necesita un inicio aleatorio y verificación de patrones; la no respuesta sigue siendo una limitación, por lo que no garantiza representatividad perfecta.
State the denominator. If 60 of 200 students reply and 45 prefer later meetings, response rate is 30% and respondent preference is 75%. Preferences of the remaining 140 are unknown. Sheet 2.5 separates preference evidence from attendance evidence.
A larger sample removes bias caused by how the sample was chosen. · Una muestra más grande elimina el sesgo causado por cómo se seleccionó la muestra.
Increasing sample size alone does not remove systematic selection or nonresponse bias. Examine and improve the collection method and disclose remaining limits. · Aumentar el tamaño de la muestra solo no elimina sesgos de selección sistemática ni de no respuesta. Examina y mejora el método de recolección y revela los límites restantes.
A truncated category-bar axis changes the visible comparison of heights. Use a zero baseline for straightforward magnitude comparisons, and make any exceptional scale choice explicit. A larger sample does not by itself fix a systematically selected sample.
A bar chart's vertical axis starts at 40 rather than 0. What must you do? · El eje vertical de un gráfico de barras comienza en 40 en lugar de 0. ¿Qué debes hacer?
A truncated category-bar scale can exaggerate relative heights. A zero baseline supports magnitude comparisons; any exception needs a clear, justified scale rather than an unstated change. · Una escala de barras truncada puede exagerar las alturas relativas. Una línea base de cero apoya comparaciones de magnitud; cualquier excepción necesita una escala clara y justificada en lugar de un cambio no declarado.