Week 2: Introduction to Statistics Flashcards
What are the levels of measurement?
Nominal - weakest, attributes are only named (categorical)
Ordinal - attributes can be ordered
Interval - distance is meaningful
Ratio - absolute zero
Why should you care about research and statistics?
Research is the backbone of evidence-based clinical practice
Statistics is the backbone of quantitative research
What is data?
Conveys information
Data is what we analyze to answer research questions
Data comes in many forms - responses on a survey, administrative data,
interviews, data from experiments , photos, interview transcripts, observed
data, etc.
What is nominal level and what are examples?
Nominal level variables are basically categories, so these types of variables are sometimes called “categorical.”
Examples of nominal data: Blood type, eye colour, cities, movie genres
What is ordinal level and what are examples?
Ordinal level variables are categorical variables that are measured in a manner that implies an order
among them
ex. if one measured income as low, middle, or high, we would say that income was measured as an ordinal
level variable.
happiness is measured as an ordinal level variable – a score of 1 is lower than a score of 2, and a score of 2 is lower than a score of 3, but one does not know whether the
distance between 1 and 2 is the same as the distance between 2 and 3.
What is interval level and what are examples?
Interval level variables are variables for which the
distance between two scores is known but there is
no true zero.
Examples of interval level variables are
temperature in degrees Centigrade, standardized
test scores like the MCAT or GRE
What is ratio level and what are examples?
Ratio level variables have both a known distance
between any two values of the variable and a
known or true zero.
Examples of ratio level variables include weight,
pulse, height, and income measured in dollars.
Notice that if income is measured as low, middle,
and high, income is an ordinal level variable but if
income is measured in dollars it is a ratio level
variable.
Which levels of measurement are considered categorical?
Nominal level and ordinal variables are categorical variables.
Ordinal variables are sometimes treated as continuous variables incorrectly
Which levels of measurement are considered continuous?
Interval, and ratio level variables are continuous variables.
What is primary data?
Data Collected First-Hand: Data that is collected
directly by the researcher for a specific study.
Examples include surveys, experiments,
observations, or interviews
What is secondary data?
Existing Data: Data that has already been collected
by others and is reused for a new research purpose.
Examples include government reports, academic
papers, historical records, or datasets from previous
studies.
any meta-analysis, analysis, reviews, research-on-research
What is a population?
The whole group of people, items, or element of interest; everyone who meets the inclusion/exclusion criteria
ex. all nursing students at ubco
What is a sample?
A subset of the population that researchers select and include in their study; who ends up in the study
ex. 20% of nursing students who responded to a survey
What is the relationship between a population and a sample?
Populations are very large and are difficult to access so we create samples drawn from the population. There are
various kinds of samples and some will provide a
more accurate population estimate of our variable
than others.
What’s a research question?
Addresses a problem, should be precise and answerable
Quantitative research questions have a hypothesis
and may or may not be explicitly stated in research papers
