Data Analysis Flashcards
7 cards from real STP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Data Analysis flashcards as text
A researcher finds a p-value of 0.03. This means:
Answer: There is a 3% probability of obtaining these results if the null hypothesis is true
A p-value represents the probability of obtaining the observed results (or more extreme) assuming the null hypothesis is true.
Which type of error occurs when a true null hypothesis is incorrectly rejected?
Answer: Type I error
A Type I error (false positive) occurs when the null hypothesis is rejected despite being true, with probability equal to alpha.
In receiver operating characteristic (ROC) analysis, an AUC of 0.5 indicates:
Answer: A test no better than random chance
An AUC of 0.5 corresponds to the diagonal line, meaning the test performs no better than random chance at discrimination.
What does a box-and-whisker plot's interquartile range (IQR) represent?
Answer: The middle 50% of the data
The IQR spans from the 25th to the 75th percentile, encompassing the middle 50% of observations.
When laboratory data shows positive skewness, the appropriate measure of central tendency is:
Answer: Median
The median is preferred for skewed data as it is not influenced by extreme values that pull the mean in the direction of the skew.
In a method validation study, 'trueness' refers to:
Answer: The closeness of agreement between the mean result and the true value
Trueness describes systematic closeness of the measured mean to the accepted reference value, distinct from precision.
Which of the following is an example of confounding in a research study?
Answer: A variable that is associated with both the exposure and the outcome
A confounder is a variable associated with both the exposure and outcome that can distort the observed relationship between them.