Sampling Techniques
What is Stratified Sampling
a method used to divide a population into subgroups and individuals are selected randomly from each subgroup. This is so that each "stratum," or subgroup, is represented appropriately in the sample.
What is Data
a set of observations
What is a Variable
a characteristic of interest for each individual in a population
What are Quartiles
numbers that divide a data set into quarters; numbers may not always be apart of the data
What is the Mode
the value that appears the most frequently in a data set
What is Systematic Sampling
a sampling method in which individuals are selected every kth number
What is Qualitative Data
What is the Explanatory Variable
the independet variable in an experiment that is controlled by the researcher
What is the Median?
the number that divides the data set in half; Quartile 2
a measure of center that averages the data set; sum of all x/sample size
What is Cluster Sampling
a sampling method in which the population is divided into subgroups, or "clusters," and each cluster is randomly selected
What is Quantitative Data
values that can be counted or measure;
What is the Response Variable
the dependent variable of an experiment that is measured to calculate any changes by the end of the experiment
What are Outliers
an observation that does not "fit" the data; values that are too big or too small and do not represent the data very well
What is a Placebo
a fake treatment that has zero effect on the explanatory variable
What is Convenience Sampling
a sampling method in which individuals are selected because they are the easiest and most accessible; easily results in bias
What are the two types of Quantitative Data?
discrete and continuous
What is a Lurking Variable
a variable that is neither the explanatory or response variable but has an effect on a study
What is the IQR
Interquartile Range is the range of the middle 50% of the data; Q3-Q1; needed in order to calculate and find any outliers
What is a Statistic
a number that describes the sample
a sampling method in which every individual selected had an equal opportunity of being selected; the most desired sampling technique
What is a Sample
a portion of the population that is to be studied
What is Double-Blinding
when both the patients and researchers are "blind" from knowing who recieves which treatments
What is a Box Plot
a graph that represents the data and allows the viewer to visualize the middle 50% of the data
What is a Parameter
a number that describes a population; is not always easy to find