Biostats 100A Midterm 1 UPDATED
ACTUAL Exam Questions and CORRECT
Answers
Data taxonomy - CORRECT ANSWER - Categorizing data into a standardized format
with common meaning so it can be standardized to introduce convenience and reduce wasted
efforts in trying to establish common definitions and context
Quantitative vs. Qualitative
Quantitative data - CORRECT ANSWER - Data associated with mathematical models and
statistical techniques used to analyze spatial location and association.
Numerical
Qualitative - CORRECT ANSWER - relating to, measuring, or measured by the quality of
something rather than its quantity.
Ex. Words measurement (color)
Continuous data - CORRECT ANSWER - Data that can take on any value. There is no
space between data values for a given domain. Graphs are represented by solid lines.
Discrete data - CORRECT ANSWER - Data with space between possible data values.
Graphs are represented by dots.
Stevens' scale of data classification - CORRECT ANSWER - Nominal vs. Ordinal vs.
Interval vs. Ratio
Nominal Data - CORRECT ANSWER - Categorical data without order Ex. Country,
School you are from; Simply categories to group data without order
, Ordinal data - CORRECT ANSWER - data exists in categories that are ordered but
differences cannot be determined; addition/subtraction and mult/division is useless/ meaningless
Grade: A, B, C
Interval data - CORRECT ANSWER - Differences between values can be found, but there
is no absolute 0. (Temp. (F and C) and Time in day; year)
Not categorical but can be ordered and add/subtracted
Ratio data - CORRECT ANSWER - data with an absolute 0. Ratios are meaningful.
(Length, Width, Weight, Distance)
Ex. temp in K
Data is not categorical but can be ordered, add/sub, and multi/divide
Probability (Random) Sampling - CORRECT ANSWER - every member of the population
of interest has an equal chance of being selected
Non-probability sampling - CORRECT ANSWER - a sampling technique in which there is
no way to calculate the likelihood that a specific element of the population being studied will be
chosen
Ex. Selecting first 50 from 100; not randomly ordered
Not random, can predict
non-response bias - CORRECT ANSWER - bias introduced to a sample when a large
fraction of those sampled fails to respond
Simple Random Sampling (SRS) - CORRECT ANSWER - A sampling procedure in which
each member of the population has an equal probability of being included in the sample.
Sampling without replacement vs. Sampling with replacement
Ex. Random number generator to select into control vs. experimental
Does not guarantee equal groups
ACTUAL Exam Questions and CORRECT
Answers
Data taxonomy - CORRECT ANSWER - Categorizing data into a standardized format
with common meaning so it can be standardized to introduce convenience and reduce wasted
efforts in trying to establish common definitions and context
Quantitative vs. Qualitative
Quantitative data - CORRECT ANSWER - Data associated with mathematical models and
statistical techniques used to analyze spatial location and association.
Numerical
Qualitative - CORRECT ANSWER - relating to, measuring, or measured by the quality of
something rather than its quantity.
Ex. Words measurement (color)
Continuous data - CORRECT ANSWER - Data that can take on any value. There is no
space between data values for a given domain. Graphs are represented by solid lines.
Discrete data - CORRECT ANSWER - Data with space between possible data values.
Graphs are represented by dots.
Stevens' scale of data classification - CORRECT ANSWER - Nominal vs. Ordinal vs.
Interval vs. Ratio
Nominal Data - CORRECT ANSWER - Categorical data without order Ex. Country,
School you are from; Simply categories to group data without order
, Ordinal data - CORRECT ANSWER - data exists in categories that are ordered but
differences cannot be determined; addition/subtraction and mult/division is useless/ meaningless
Grade: A, B, C
Interval data - CORRECT ANSWER - Differences between values can be found, but there
is no absolute 0. (Temp. (F and C) and Time in day; year)
Not categorical but can be ordered and add/subtracted
Ratio data - CORRECT ANSWER - data with an absolute 0. Ratios are meaningful.
(Length, Width, Weight, Distance)
Ex. temp in K
Data is not categorical but can be ordered, add/sub, and multi/divide
Probability (Random) Sampling - CORRECT ANSWER - every member of the population
of interest has an equal chance of being selected
Non-probability sampling - CORRECT ANSWER - a sampling technique in which there is
no way to calculate the likelihood that a specific element of the population being studied will be
chosen
Ex. Selecting first 50 from 100; not randomly ordered
Not random, can predict
non-response bias - CORRECT ANSWER - bias introduced to a sample when a large
fraction of those sampled fails to respond
Simple Random Sampling (SRS) - CORRECT ANSWER - A sampling procedure in which
each member of the population has an equal probability of being included in the sample.
Sampling without replacement vs. Sampling with replacement
Ex. Random number generator to select into control vs. experimental
Does not guarantee equal groups
