CPXP Exam Module 2 - Measurement & Analysis Flashcards
Measurement & Analysis
What are the components of an effective measurement system?
Observation, question, hypothesis, test/experiment, analysis, conclusions
What is a hypothesis?
A stated prediction about a specified outcome
What are some sources of bias in measurement and analysis?
Cultural biases, erroneous assumptions, ego-based, inaccurate observations
What are the two basic data types?
Quantitative (numbers) and qualitative (words)
What are the advantages of quantitative data?
Structured, test hypotheses or assumptions, answers “what” and “how”, high cerebral impact
What are the advantages of qualitative data?
Description, dynamic, observations and interviews, themes, answers “why” and “how” questions, high emotional impact
What is mixed-methods?
The use of a combination of qualitative and quantitative measurement and analysis methods
What are some of the ethical challenges in measurement?
Bias, under-reporting, over-reporting, using unreliable or invalid measures or methods, and not using the data for assessment or improvement
What is your biggest ethical responsibility in using measures?
Protection of patients and families
Define “validity” in practical terms- what makes a measure “valid” or “validated”?
The measure accurately measures the phenomenon it is supposed to measure
What is “content validity”?
How well a measurement instrument (or test) covers all relevant parts of the construct it aims to measure
What is “criterion validity?”
How well a test or instrument measures a phenomenon compared to an established standard of comparison vs. an established “gold standard” measure (a measure believed to be the best available).
What is “construct validity?”
The degree to which a test is able to measure a construct
What is a construct?
An abstract concept that is not directly observable, e.g. depression, intelligence, etc.
What are the three main types of validity?
Content, Criterion, and Construct
What is “reliability”?
The ability of a measure (or test) to consistently produce similar results under consistent conditions
What are the four types of reliability?
1) Test-retest
2) parallel forms
3) internal consistency
4) inter-rater
What is test-retest reliability?
The ability of a test or measure to yield the same results over time when measuring a consistent or fixed phenomenon
What is parallel forms reliability?
Different forms of the same test get similar results when measuring the same phenomenon
What is internal consistency reliability?
The individual items or components of a measure (e.g. on a survey or questionnaire) are significantly associated or highly related to one other (e.g. are correlated)
What is inter-rater reliability?
Different people administering the same test will get similar results when measuring the same phenomenon
What are the four types of quantitative data?
Nominal, ordinal, interval, and ratio
What is a nominal measure?
Categorical or dichotomous and non-sequential, e.g. yes/no, alive/dead, gender, etc.
What is an ordinal measure?
Categorical, sequential, and not scaled, e.g. date ranges, age groups
What is an interval measure?
Numerical, sequential, and scaled but not at equal intervals or ratios, e.g. a Likert Scale (1= disagree, 2= somewhat disagree, 3= neutral, 4= agree, 5= strongly agree)
What is a ratio measure?
A ratio measure is one that is numerical, sequential, scaled, and at equal intervals that allows ratio based comparisons of any size of increment, e.g. fully continuous data, e.g. temperature
What is a population?
A group of people within a certain demographic or set of demographics
What is a sample?
A selected subset of a given population
What is sampling?
The act of selecting and/or recruiting a sample from a given population
What are some important things to watch out for when sampling?
Sampling bias, time, feasibility, representativeness, diversity, inclusion, culture, language, literacy
What does capital “N” stand for when describing sample size?
N refers to the TOTAL overall number of participants and data points in a population- you need N to be large enough to sample adequately
What does a lower case “n” stand for in describing a sample size?
“n” refers to the size of a selected sample of a population or a subsample of a sample - a sample should be big enough to draw actionable conclusions from the data and analyses and avoid Type II error
What n size is considered an absolute minimum for most samples?
n = 30
What is Type II error?
The inability of a measure or test to detect a significant change when a significant change actually exists. This can happen when n size is too small, e.g. false negative.
What is Type I error?
An error of a measure in which the measure states that a significant change has occurred when in fact no significant change exists, e.g. “false positive”
What is a significant result?
An observed change that has a very low probability of occurring due to chance or random variation alone, usually >2 SD from the mean (less than 5% chance probability)
Descriptive Statistics
Statistics used to describe a population or sample including measures of central tendency and do not assess inferences or variation
What are the three measures of central tendency?
Mean (average), median, and mode
Define “mean” (average) and describe how it is calculated
The mean is the arithmetic average of all values in a sample. A mean is calculated by summing all of the values in the sample and dividing this by the number of observations (n) in the sample
Define median and describe how to determine it
The median is a point in a distribution of values in a sample at which 50% of the remaining values fall on either side. To determine the median, order all the values in sequence and find the middle most point in the sequence.
Define mode and describe how to determine it
The mode is the most frequently occurring value in a distribution or sample. To determine the mode, you can count the frequencies of each data value and select the highest frequency value.
When is the mean the preferred measure of central tendency?
The mean is the preferred measure of central tendency when the distribution of values in a sample is normally or near-normally distributed
When is the median the preferred measure of central tendency?
The median is preferred when the distribution of values in a sample is skewed or non-normal, or when the n size is low resulting in the ability of single outlier values to skew the mean
What is a normal distribution?
A group of values in a sample which has a “bell curve” appearance when arranged around the mean
What is a skewed distribution?
A group of values that does not have a bell curve appearance when arranged around a given mean, but rather shifts to the left or the right of the mean
What are the most common measures of variation used in inferential statistics?
Range
Standard Deviation (SD)
Variance
Define “range” and describe how to determine it
The distance between the highest and lowest values in a data distribution or sample. It is calculated as the difference between the highest and lowest values.