lab 2 Flashcards
serve as the basis of comparison
control
dependent variable data that are measured during the experiment
dependent variable
those that are controlled by the experimenter, but do not change during data collection.
independent variable
variables that are not
necessarily included in the experiment, but may impact the data collected.
external factors
involve quantitative measurements that have a mathematical relationship
to each other.
numerical data
data that
can have an infinite number of values
continuous data
have a limited (finite)
number of values
discrete data
discrete character states that have no direct numerical value
categorical data
data that is ordered but does not have a mathematical relationship.
ranked data
values that quickly summarize aspects of
our (numerical) data
descriptive statistics
typically calculated separately for each treatment or experimental group, typically designated as n
sample size
numerical average
mean
measures the average deviation of each individual value from the mean
value of that sample
standard deviation
middle value when values are ranked from low to high
median
help identify whether
the mean is indeed representative of the data collected
standard error
used to graph data when both the
independent and dependent variables are numerical.
These can be useful for examining the relationship
between two variables.
scatter plots
used when both variables are
numerical and the goal is to determine if there is a trend
in data. This can be used to determine if there are
changes in a dependent variable over time
line graphs
used
when the independent variable is discrete, ranked, or an
attribute. These graphs are useful for comparing data
sets.
bar graphs
used
when the independent variable is discrete, ranked, or an
attribute. These graphs are useful for comparing data
sets.
histograms
a common component of many types
of graphs, especially bar graphs. They are used to
represent the variability of data. They typically extend
symmetrically above and below the mean, as shown in
the example at right and the line graph above.
error bars
