Data Collection Methods - ACT Math
- What is a control group?
- A group in an experiment that does not receive the treatment. Used for comparison to measure treatment effectiveness.
- What is interval data?
- Numerical data with meaningful intervals but no true zero. Temperature in Celsius is a classic example.
- Define bias in data collection.
- A systematic error that leads to incorrect conclusions. It occurs when the sample isn't representative of the population.
- What is nominal data?
- Categorical data without a natural order. Examples include gender, color, or brand names.
- What is a longitudinal study?
- Research conducted over a long period to observe long-term effects. Tracks changes in subjects over extended time periods.
- Define experimental study.
- A study where a treatment is applied to observe its effects. This allows researchers to test cause-and-effect relationships.
- What is a sample in statistics?
- A subset of the population used to infer about the population. It's used when studying the entire population isn't practical.
- What is convenience sampling?
- Selecting individuals that are easiest to reach. This method is quick but may not represent the full population.
- What is stratified sampling?
- Dividing a population into subgroups and sampling each subgroup. This ensures representation from all relevant subgroups.
- Identify the main purpose of data collection.
- To gather information for analysis and decision-making. Data supports research, planning, and problem-solving.
- Define cluster sampling.
- Dividing population into clusters and randomly selecting entire clusters. Useful when natural groups exist within the population.
- Identify the difference between a parameter and a statistic.
- A parameter describes a population; a statistic describes a sample. Parameters are true values; statistics are estimates from samples.
- Define the term 'response rate'.
- The proportion of respondents who completed the survey. Higher rates indicate more representative results.
- What is a population in statistics?
- The entire group of individuals or items being studied. This is the total set from which samples are drawn.
- Identify the Hawthorne effect.
- Subjects alter behavior because they know they are being observed. Being observed changes how people naturally behave.
- Define placebo.
- A substance with no therapeutic effect used as a control. Helps control for psychological effects of receiving treatment.
- Define systematic sampling.
- A method where every nth individual is chosen from a list. For example, selecting every 10th person from a numbered list.
- Define ratio data.
- Numerical data with meaningful intervals and a true zero. Height, weight, and time are common examples.
- What is the purpose of random sampling?
- To reduce bias and ensure each member of a population has equal chance of selection. This prevents selection bias and improves representativeness.
- Define ordinal data.
- Categorical data with a meaningful order but no fixed intervals. Like rating scales: poor, fair, good, excellent.
- What is the purpose of data validation?
- To ensure accuracy and quality of data collected. Checks for errors, completeness, and consistency.
- What does a double-blind experiment mean?
- Neither participants nor researchers know who receives treatment. This prevents bias from expectations affecting results.
- Identify a key characteristic of reliable data.
- Consistency in results across different occasions. Reliable data gives similar results when measurement is repeated.
- Define quantitative data.
- Numerical data representing counts or measurements. This includes discrete counts and continuous measurements.
- What is the main advantage of using surveys?
- They can collect data from a large number of respondents quickly. They're cost-effective and can reach geographically dispersed groups.
- Define cross-sectional study.
- Observational study analyzing data from a population at one point in time. Provides a snapshot of a population at a specific moment.
- What is an inference in statistics?
- A conclusion drawn about a population based on a sample. Uses sample data to make predictions about the whole population.
- What is the purpose of a pilot study?
- To test the feasibility and design of a larger study. It's a small-scale trial run before the full study.
- What is an observational study?
- A study where no treatment is applied and subjects are observed. Researchers watch but don't manipulate any variables.
- What is qualitative data?
- Non-numerical data describing characteristics or qualities. Examples include colors, names, or categories.