Term | Definition |
Hypothesis | statement of the relationship among variables, not a question |
Operational definition | exactly how to measure the variable |
Collect Data | results of an experiment in numbers, needs to be usable |
Analyze results | getting the numbers through formulas |
Interpret results | the meaning, relating back to hypothesis |
Share results | publish or make public knowledge your findings |
Statistics | a set of tools concerned with the collection, organization, and analysis of data, has two branches: descriptive and inferential |
Data | the numbers |
Descriptive | describes data, ex. class average |
Inferential | to make inferences of the data, ex. our class average is all class averages on campus |
Variable | anything that can take on different values or amounts, two types: independent and dependent |
Independent | the researcher manipulates, control or experimental group, used to group people |
Dependent | measurement of behavior, effect not cause |
Correlation | relationship between two variables |
population | complete collection of anything, regardless of size of collection |
sample | subset of population, measured to talk about populations, goal to be unbiased |
mean | mew |
number of anything | N |
parameters | numerical summary characteristics of population, can measure about a populations |
statistics | numerical summary characteristics of a sample |
mean of sample | - over x |
scaling | the assigning of numbers to objects or events |
4 scales of measurements | nominal scale, ordinal scale, interval scale, ratio scale |
nominal scale | assigns a name or label to objects or events, can be #'s, ex. barcodes |
ordinal scale | objects or events in rank order, just rank alone, not equality, ex. favorite bands |
interval scale | equal intervals between number, ranks are equal, ex. degrees f to c |
ratio scale | zero means absence of measurements, true zero, ex. height |
Frequency Distribution | creating a table of the data that shows the number of times a given group of scores occurs, construction varies, all have x and f columns, |
x | variable |
f | frequency |
cf | cumulative frequency |
cumulative frequency | number of times a value occurs up to and including that frequency |
rf | relative frequency |
relative frequency | the proportion of people on each row, always adds to one |
percentage | rf x 100 |
crf | cumulative relative frequency |
cumulative relative frequency | rf up to and including all values, add to one |
c% | crf x 100, % of people up to and including any score level |
results of frequency distribution | lost almost all richness, organized |
graphing | must label axis, y axis should be 3/4 that of x axis, y axis should use full range, always start y axis at zero |
histogram | bars touch, good with graphed frequency distribution |
line graph | connect the points |