Exam 2 - Chapter 11 Flashcards
what are the stages in data analysis?
- prepare data for analysis
- describe the sample
- test reliability of measurement methods
- conduct exploratory analysis
- conduct confirmatory analysis
what does probability theory entail?
- explains the extent of a relationship between variables
- the probability that an event can be accurately predicted
decision theory is best used under which circumstance?
when testing for differences between groups of the same population
define normal curve
it is the theoretical frequency distribution of all possible values in a population
define level of statistical significance
the level at which the statistical results indicate a significant difference between groups
also called alpha or cutoff point
mode, mean, and median are equal in a normal distribution curve
true
what does the theory of normal curve state?
any data score will be within a certain range of a mean value
define inference
a conclusion or judgment made based on evidence
what is the two-tailed test of significance?
the analysis of a nondirectional hypothesis
what are the components of a one-tailed test of significance?
- directional hypothesis
- extreme statistical values in a single tail that occur are of interest
one-tailed tests are more powerful than two-tailed tests
true
what is a type I error?
null hypothesis is wrongfully rejected
similar to wrongful accusation
how does type I error occur?
results wrongfully indicate there is significant difference
reliability is a result of consistency
true
validity is a result of accuracy
true
data saturation is associated with qualitative studies
true
power analysis is associated with quantitative analysis
true
how does type II error occur?
the null hypothesis is regarded as true but is in fact false
what does power mean in research?
the probability that a statistical test will detect a significant difference
what are the 4 parameters of a power analysis?
- power
- level of significance
- effect size
- sample size
define effect size
- the degree to which the phenomenon is present in the population
- the degree to which the null hypothesis is false
what are the types of statistics in research?
- descriptive
- inferential
what are descriptive statistics?
these are summary statistics that allow the researcher to organize data in ways that give meaning
what do inferential statistics entail?
addresses objectives, questions, and hypotheses to allow inference from the study sample to the target population
what are the 3 things that inferential statistics assist in?
- identifying relationships
- examining predictions
- determining differences between groups in studies
what is another name for descriptive statistics?
summary statistics
analysis in simple descriptive studies is only limited to descriptive statistics
true
what are the measures of dispersion?
- range
- variance
- standard deviation
- confidence interval
- standardized scores
- scatterplots
what are the types of frequency distributions?
- ungrouped
- grouped
- percentage
what does frequency distribution describe?
the occurrence of scores or categories in a study
what are the types of inferential statistics?
- Pearson Product-Moment Correlation
- Factor Analysis
- Regression Analysis
- Chi-square
- t-Test
- Analysis of Variance
what does the Pearson Product-Moment Correlation test for?
the presence of a relationship between two variables
what are the results that Pearson present?
- nature of the relationship between two variables (positive / negative)
- magnitude of the relationship (-1 to +1)
- the significance of a correlation coefficient
what does the r value indicate?
the degree of relationship between the two variables
what is a significant characteristic of PPMC?
it is symmetrical
define symmetrical
the analysis does not identify a direction of the relationship
why is regression analysis used?
to predict the value of one variable based on the value of other variables
what is the variable that is predicted in a regression analysis?
dependent variable
post-hoc analyses are only conducted with how many groups in a study?
three groups are more
what does the Analysis of Variance (ANOVA) entail?
tests for differences between variance in 3 groups or more
why is ANOVA more flexible than other types of analysis?
it can examine data from 3 or more groups
what does t-Test entail?
testing for significant differences between two samples only
what is the most commonly used test of differences?
t-Test
chi-square test is best used for which type of data?
- nominal
- ordinal
what does the chi-square test need in order to be effective?
expected and observed frequencies
what does the chi-square test determine?
whether two variables are independent or related
how can you decrease the risk of a type II error?
use large sample sizes
which types of measurement works well with t-Test?
- ratio
- interval
what is the purpose of an analysis?
examine differences among the groups included in a study
which type of data is used for ungrouped frequency distribution?
discrete data
which type of data is used for grouped frequency distribution?
continuous data
examples of discrete data
- age
- marital status
- gender
- ethnicity
examples of continuous data
- temperature
- vital lung capacity
- weight
- scale
- time
how is range obtained?
subtract the lowest score from the highest score
what does variance indicate?
the spread or dispersion of scores (that are calculated in a study)
what is standard deviation?
- the square root of the variance
- the average difference value
what is confidence interval?
the probability of including the value of the population within an interval estimate
what does the confidence interval calculate?
upper and lower ends of an interval
what are standardized scores?
numbers that make sense only within the framework of measurements used within a specific study
what does a z-score express?
deviations from the mean in terms of standard deviation units
what does a scatterplot illustrate?
- the dispersion of variables
- the relationship between values on different variables
