Quantitative Data Analysis Flashcards
what are the two levels statistical analysis?
descriptive
inferential
what is descriptive statistical analysis used for?
used to summarize the data
what is inferential statistical analysis used for?
used to draw conclusions about population parameters based on data from a sample
what are types pf descriptive measurements?
frequency distribution
measures of central tendency
measures of dispersion/variability
what is frequency distribution?
Frequency distribution in research is a way of organizing and summarizing data to understand patterns or trends within a dataset. It involves grouping data into categories or intervals and counting the number of observations that fall into each category.
what is measures of central tendency?
statistical tools used to describe the center or average of a dataset. (mean, median, mode)
what are measures of dispersion?
statistical tools used to describe the spread or variability of a dataset. They help researchers understand how spread out the values are from the central tendency measures
ex: standard deviation, range
what are distributions for statistics?
normal
T
skewed
what is a normal distribution?
a specific pattern that many natural phenomena tend to follow when measured. It’s often called a “bell curve” because when graphed, it forms a symmetrical, bell-shaped curve
what is T-distribution?
a probability distribution that is similar to the normal distribution but is used when the sample size is small or when the population standard deviation is unknown.
what is skewed distribution?
a distribution of data that is asymmetrical, meaning it is not evenly balanced around its central value. Instead, the data is stretched out more to one side than the other
what are examples of measures of association?
correlation coefficient
Spearman Rank Correlation
Odds ratio/relative risk
what is correlation coefficient?
a numerical measure that describes the strength and direction of the relationship between two variables. It tells us how much and in what way two variables change together.
what is spearman rank correlation?
a statistical method used to measure the strength and direction of the relationship between two variables. It’s specifically designed to assess the association between variables when the data is not normally distributed or when the relationship is non-linear.
what is odds ratio/relative risk?
relationship between two
categorical variables
what data is spearmans rank correlation used with?
ordinal data
what is ANOVA?
a statistical test used to compare the means of
two or more independent samples (using the F distribution)
what are hypotheses?
Predictions the researcher makes about the expected relationships
what is the intent of hypotheses?
reject the null hypothesis, thus proving the alternative
hypothesis
what determines whether a null hypothesis can be rejected?
statistical significance
what is a p value?
a measure of the probability that an observed
difference could have occurred just by random chance
what does a lower p value mean?
the greater the statistical
significance of the observed difference
what does a P less than .05 mean?
regarded as unlikely enough to reject the null hypothesis, it is “statistically significant at the 0.05 or 5%
level”
what does a p value greater than .05 mean?
not enough evidence to reject the null hypothesis,
“statistically non-significant
sample size needed to test ta hypothesis depends on what 4 factors?
- expected difference between two groups
- Variability of the data
- Power of the study = probability that any difference is real
(usually at least 80%) - Level of significance accepted (usually 5%)
