Research Methods Flashcards
(76 cards)
What is a Population in quantitative research?
The entire group being studied; statistics describe what is happening with that group.
What is a Sample in quantitative research?
A smaller, representative group from the population; findings from samples are generalized to the population.
What are Measures of Central Tendency?
Mean, Median, Mode; they indicate where data clusters are.
What is the Mean?
The average (sum ÷ count).
What is the Median?
The middle value in an ordered set; if two, average them.
What is the Mode?
The most frequent value.
What are Measures of Spread?
Range & Standard Deviation; Show data dispersion around central tendency.
What is the Range?
Difference between the smallest and largest values.
What is Standard Deviation (SD)?
How close the values in a data set are to the mean. Low SD = clustered around mean; High SD = data is spread out.
What is Descriptive analysis?
Descriptive analyses summarize existing data; display data; communicate data; describes ‘what is’ at the time of the observation/study. (What’s happening)
What is Inferential analysis?
These analyses are from samples, draw inferences to populations; from limited info, make estimated guesses. Generalize to what is not observed (What can be, what can happen if…)
What is Correlation?
Indicates a relationship between two variables without implying causation. Typically illustrated with scatterplots
What is the Pearson-Product-Moment Correlation (r)?
A measure of the linear relationship between two variables that have been measured on interval or ratio scales. Formula: Covariance ÷ (Standard Deviation (SD) of both variables).
What does a Positive correlation indicate?
Higher values on one variable correspond to higher values on the other variable.
What does a Negative correlation indicate?
Higher values on one variable correspond to lower values on the other variable.
What is the range of r in correlation?
The range of r is -1.0 to +1.0.
What does a value close to 0 in correlation indicate?
Indicates a weak linear relationship.
What does a value close to ±1 in correlation indicate?
Indicates a strong linear relationship.
What is Ordinal Data?
Rank-ordered data; no equal intervals between units. (Percentiles, grades, race placements)
What is Nominal Data?
Categories with no logical order; used to label or classify. (Hair color, eye color, instrument choice)
What is Interval Data?
Equal intervals; no true zero. (Temperature, summed rubric data)
What is Ratio Data?
Refers to variables that can take on any numerical value. (Weight, height, time, decimals/fractions)
What is a Histogram?
Graphical representations of quantitative data showing how often each value occurs. (X axis = Measurable Data; Y axis = Frequency)
What is Normal Distribution?
Symmetrical, bell-shaped curve where Mean = Median = Mode.