Data/Sampling
This data type includes numeric values that can be added or averaged meaningfully.
What is quantitative data?
This is the simplest measurement scale, classifying data into distinct groups without any order.
What is the nominal scale?
A positive correlation means that as one variable increases, this happens to the other.
What is it increases?
The portion of the group that a researcher is interested in studying.
What is the sample?
The average of a set of numbers.
What is the mean?
This sampling method divides the population into subgroups and randomly selects from each.
What is stratified sampling?
This scale involves ordering data but does not measure the exact differences between values.
What is the ordinal scale?
This method uses past data to predict future values.
What is forecasting?
This is the claim that is tested in a hypothesis test.
What is the null hypothesis?
The middle number when data is ordered.
What is the median?
This type of sampling gives every member of the population an equal chance of being chosen.
What is simple random sampling?
This scale has equal intervals but no true zero point, like temperature in Celsius.
What is the interval scale?
A correlation coefficient of 0 means this.
What is no linear relationship?
This type of error occurs when you reject a true null hypothesis.
What is a Type I error?
The most frequently occurring number in a dataset.
What is the mode?
What kind of data results from counting rather than measuring?
What is discrete data?
This scale has equal intervals and a true zero, allowing for meaningful ratios.
What is the ratio scale?
In a seasonal time series, this component reflects regular fluctuations within a year.
What is the seasonal component?
If the p-value is less than alpha, you should do this.
What is reject the null hypothesis?
This measures how much the data values vary from the mean.
What is variance?
Temperature and weight are examples of this type of quantitative data.
What is continuous data?
Classify the following examples by their measurement scale:
Shirt sizes (S, M, L)
Annual income in dollars
What Ordinal (shirt sizes) and Ratio (income)?
Choosing only participants likely to give favorable responses violates this ethical principle of fair representation.
What is sampling bias (or lack of representativeness)?
You want to test whether the average delivery time of a service is different from 30 minutes. The sample size is 20, the population standard deviation is unknown, and data is approximately normal. This is the appropriate test to use.
What is a one-sample t-test?
This statistic measures both direction and strength of linear relationship between two variables.
What is covariance?