Terms : Hide Images
| 249994613 | population | the entire group of individuals about which we want information | |
| 249994614 | sample | the part of the population from which we actually collect information | |
| 249994615 | convenience sample | interviewer chooses individuals who are easiest to reach | |
| 249994616 | bias | occurs when the design of a study systematically favors certain outcomes | |
| 249994617 | voluntary response sample | consists of people who choose themselves by responding to a general appeal | |
| 249994618 | simple random sample (SRS) | is chose so that every set of n individuals has an equal chance to be the sample already selected | |
| 249994619 | table of random digits | a long string of digits such that each entry in the table is equally likely to be any of the 10 digits 0-9 and the entries are independent of each other | |
| 249994620 | stratified random sample | an SRS is chosen groups of similar individuals called strata | |
| 249994621 | cluster sample and clusters | divide the population into smaller groups which mirror the characteristics of the population. Then an SRS of the clusters is chosen | |
| 249994622 | strata | are similar within, but different between | |
| 249994623 | clusters | are similar between but different within | |
| 249994624 | inference | the process of drawing conclusions about a population on the basis of sample data | |
| 249994625 | sampling frame | the list of individuals from the sample is drawn | |
| 249994626 | undercoverage | occurs when some groups in the population are left out of the sampling process | |
| 249994627 | nonresponse | occurs when a chosen individual can't be contacted or refuses to participate | |
| 249994628 | response bias | a systemic pattern of incorrect responses in a sample survey | |
| 249994629 | observational study | observes individuals and measures variables of interest | |
| 249994630 | experiment | deliberately imposes some treatment on individuals to measure their responses | |
| 249994631 | lurking variable | a variable that is not among the explanatory or response variables in a study but that may influence the response variable | |
| 249994632 | confounding | occurs when two variables are associated in such a way that their effects on a response variable cannot be distinguished from each other | |
| 249994633 | treatment | specific condition applied to the individuals in an experiment | |
| 249994634 | experimental units | the smallest collection of individuals to which treatments are applied | |
| 249994635 | subjects | human experimental units | |
| 249994636 | factors | explanatory variables | |
| 249994637 | random assignment | experimental units are assigned to treatments using a chance process | |
| 249994638 | completely randomized design | the treatments are assigned to all the experimental units completely by chance | |
| 249994639 | control group | provides a baseline for comparing the effects of the other treatments | |
| 249994640 | replication | using enough experimental units to be sure that results did not happen by chance | |
| 249994641 | placebo effect | the response to a dummy treatment | |
| 249994642 | double-blind experiment | neither the subjects nor those who interact with them and measure the response variable know which treatment a subject received | |
| 249994643 | single-blind experiment | the subjects are unaware of which treatment they are receiving, but the people interacting with them and measuring the response do know | |
| 249994644 | statistically significant | an observed effect so large that it would rarely occur by chance is | |
| 249994645 | block | a group of experimental units that are known before the experiment to be similar in some way that is expected to affect the response to the treatments | |
| 249994646 | randomized block design | the random assignment of experimental units to treatments is carried out separately within each block | |
| 249994647 | matched pairs design | blocks are created by matching pairs of similar experimental units |
