Stastics - ✔✔ empirical or practical method for collecting, organizing, summarizing and presenting data & for making inferences about the population
... [Show More] from which the data is drawn
Probability - ✔✔ Likely-hood that something will happen
Population - ✔✔ An entire group of individuals that a researcher wants to study
Sample - ✔✔ A subset of those individuals selected from a population from which an investigator draws conclusions that are used to understand the population
What is an example of a population study? - ✔✔ The U.S. census
Parameters - ✔✔ The numerical measurements taken from the population
Inferential statistics - ✔✔ Allows a researcher to generalize the results from a sample to a population through hypothesis testing
Hypothesis testing - ✔✔ Examining data to determine whether there is sufficient evidence to reject the null hypothesis
Random Sampling - ✔✔ Method of selecting subjects base don chance alone and is the strongest approach to sampling
Simple random sampling - ✔✔ Taken so that all subjects in a population have an equal probability of being selected
Systematic Random Sampling - ✔✔ Beings w/ assigning a number to each subject in the population and then selecting every 'nth' person (where n is the population size divided by the desired sample size)
Stratified Random Sampling - ✔✔ Is useful when the researcher wants to ensure that certain groups are represented equally in the sample - divide the population into groups - called strata - ex. the researcher will divide pts by gender groups and then randomly select patients from each gender group
A stratified random sample is _______________ if the subject size of each stratum in the sample is in proportion to that in the population - ✔✔ Proportionate
A stratified random sample can be _________________ if the subject size of each stratum in the sample is non proportionate to that of the population - ✔✔ Non-proportionate
Cluster Sampling - ✔✔ Similar to stratified sampling - is particularly useful when a population is large - works better when subjects in a cluster of heterogenous
In general, cluster sampling provides _______ ____________ than simple random sampling or stratified sampling - ✔✔ Less precision - but more cost-effective and feasible approach
Nonrandom Sampling - ✔✔ Members of the population do not have an equal chance of selection - prioritize feasibility or access
Convenience Sampling - ✔✔ Non-random sampling - Based on the accessibility of subjects in the population - ex. using every student in a since course at a university (less likely to be representative of the population)
Volunteer Sampling - ✔✔ Nonrandom sampling method where participants self-select into the sample
Quota sampling - ✔✔ Nonrandom sampling - dividing the population into mutually exclusive (not overlapping) groups and selecting subjects from each group (the same as stratified random sampling, but it's not random) - can limit generalizability
Snowball Sampling - ✔✔ Nonrandom sampling - Uses word of mouth, nomination, or referral to accrue subjects - useful for finding hidden subjects
Sampling distribution - ✔✔ Distribution of a statistic that is computed from samples
Sampling error - ✔✔ The difference between population mean, n and the sample mean - can affect our statistical estimate - when large, it means there is a lot of variability in the sampling distribution
Confidence level - ✔✔ The level of assurance a researcher has that data from a study/studies represent true values
Power analysis - ✔✔ Procedure to calculate the minimum sample size - should be performed before beinning a study
Variable - ✔✔ Trait or characteristics that varies or changes
Data - ✔✔ Values or variables when they vary
Data set - ✔✔ A collection of data values
Qualitative variables - ✔✔ Values that are nonnumeric
Quantitative variables - ✔✔ Values that are numeric
Discrete variables - ✔✔ (Numeric variables) values that are countable but do not include the fractions between countable categories
Continuous variables - ✔✔ Have every possible value on a continuum
Independent variable - ✔✔ The variable being manipulated by the investigator or affects another variable
Depdendent variable - ✔✔ Is affected by an independent
Levels of measurements - ✔✔ Nominal, ordinal, interval, ratio
Nominal LOM - ✔✔ Data is classified into mutually exclusive categories where no ranking or ordering is imposed on categories (Gender, ethnicity, ZIP code, religion, medical diagnosis, names of medicines) [Show Less]