Stats Vocab

the study of how to collect, organize, analyze, and interpret numerical info from data

people or objects being studied

characteristic of the individual to be measured or observed

has a value or numerical measure for which operations such as addition or averaging make sense

describes an individual by placing the individual into a category or group (eg male or female)

data are from EVERY individual of interest

data are from only SOME of the individuals

numerical measure that describes an aspect of a population

numerical measure that describes an aspect of a sample

levels that indicate the type of arithmetic that is appropriate for the data (ordering, taking differences, taking ratios)

applies to data that consists of names, labels, or categories

applies to data that can be arranged in order. However, differences between data values either cannot be determined or are meaningless

applies to data that can be arranged in order. In addition, differences between data values are meaningful

applies to data that can be arranged in order. In addition, both differences between data values and ratios of DV are meaningful. Data at the ratio level have a true zero

involves methods of organizing, picturing, and summarizing info from samples or population

involves methods of using info from a sample to draw conclusions regarding the population

a subset of a population selected in a manner such that every section sample of size n from the population has an equal chance of being selected

numerical facsimile or representation of a real-world phenomenon

a table of numbers that makes it easier to select numbers in a random sample

although a number is selected for the sample, it is not removed from the population (the same number may be selected for the sample more than once)

divide the entire population into distinct subgroups called strata. The strata are based on shared characteristics such as age, income, and education level. Draw random samples from each stratum

number all members of the population sequentially. Then, from a starting point selected at random, include every kth member of the population in the sample

divide the entire population into pre-existing segments or clusters. The clusters are often geographic. Make a random selection of clusters. Include every member of each selected cluster in the sample

use a variety of sampling methods to create successively smaller groups at each stage. The final sample consists of clusters

a list of individuals from which a sample is actually selected

results from omitting population members from the sample frame

the difference between measurements from a sample and corresponding measurements from the respective population. It is caused by the fact that the sample does not perfectly represent the population

the result of poor sample design, sloppy data collection, faulty measuring instruments, bias in questionnaires, and so on

measurements or observations from the entire population are used

measurements or observations from part of the population are used

observations and measurements of individuals are conducted in a way that doesn’t change the response or the variable being measured

treatment is deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured

occurs when a subject receives no treatment but (incorrectly) believes he or she is in fact receiving treatment and responds favorably

one in which a random process is used to assign each individual to one of the treatments

create a sample by using data from population members that are readily available

a group of individuals sharing some common features that might affect the treatment

individuals are first sorted into blocks, and then a random process is used to assign each individual in the block to one of the treatments

group not given treatment, but everything else is the same so that any difference in variable(s) can be attributed to the treatment

used to assign individuals to the two treatment groups. This helps prevent bias in selecting members for each group

repeating of an experiment on many patients to reduce the possibility that the observed changes occured by chance alone

group that is given the treatment

two variables whose individual effects cannot be distinguished

one for which no data have been collected but that nevertheless has influence on the other variables in the study

neither the subject nor the observer knows which subjects are receiving treatment

a process of gathering data by asking questions

individuals either cannot be contacted or refuse to participate. Can result in significant undercoverage of a population

individuals with strong feelings about a subject are more likely than others to respond. Such a study is interesting but not reflective of the population

the question may be worded in such a way as to elicit a specific response. The order of questions might lead to biased responses

results that are valid for a particular group may or may not be valid for a different group

the sponsor of a study may advertently or inadvertently affect the outcomes or finding