Frequencies
This term describes how often something occurs in a sample.
What is frequency?
This type of study simply watches subjects and records measurements without assigning treatments.
What is an observational study?
This sampling method relies on people deciding for themselves to join the sample after a general invitation.
What is a voluntary sample?
This measure is calculated by summing all values and dividing by the number of observations.
What is the mean?
This unseen third factor influences both the explanatory and response variables, potentially creating a false association.
What is a confounding variable?
This is the ratio of a category's frequency to the total number of observations.
What is relative frequency?
This kind of study deliberately assigns treatments or conditions to participants so researchers can measure the effects.
What is an experimental study?
This sampling method picks participants who are easiest to reach or contact.
What is a convenience sample?
This measure is the middle value when data are ordered from least to greatest.
What is the median?
This variable is used to predict or explain changes in another variable.
What is an explanatory (independent) variable?
This measures the frequency of one variable in relation to another, often found by dividing a cell count by the grand total.
What is joint relative frequency?
This effect occurs when a patient shows improvement after receiving an inert treatment, because they believe the treatment works.
What is the placebo effect?
This sample is chosen so every possible group of nn individuals from the population has an equal chance to be selected.
What is a simple random sample (SRS)?
This measure is the value that occurs most frequently in a dataset.
What is the mode?
This variable's value is predicted or explained by the explanatory variable.
What is a response (dependent) variable?
This is found by dividing a row total or column total by the overall number of observations.
What is marginal frequency?
This practice keeps participants, researchers, or both unaware of who received which treatment to reduce bias.
What is blinding?
This method divides the population into non-overlapping groups based on shared characteristics, takes an SRS from each group, and combines them.
What is a stratified random sample?
This represents the highest value in a dataset.
What is the maximum?
This variable places individuals into named groups or categories based on qualities rather than numbers.
What is a categorical variable?
This ratio compares a joint relative frequency to its corresponding marginal relative frequency (answers "given that" questions).
What is conditional relative frequency?
A specific inquiry which the research seeks to provide a response to.
What is a Research Question?
This method splits the population into geographically (or naturally) grouped clusters, randomly selects some clusters, and includes all members of those clusters.
What is a cluster sample?
This statistic quantifies the average amount that data values differ from the mean (a measure of spread).
What is the standard deviation?
his variable measures numeric amounts like height, weight, or age.
What is a quantitative variable?