Reporting and Critical Evaluation of Biological Research 3.3 Flashcards
what can variables give rise to?
- quantitive data
- qualitative data
- ranked data
how is quantitative data obtained?
objectively with instruments and have numerical values
qualitative data are what?
- subjective
- descriptive
- based on observation
what is ranked data referred to?
the data transformation in which numerical values are replaced by their rank when the data are stored from lowest to highest
the type of variable being investigated determines what?
the graphical display or statistical tests that may be used
what is the arithmetic mean?
the average of a data group
what is the median?
the middle value, with equal numbers of data below and above it
what is the mode?
the most common value of category
why are box plots used?
to show variation within and between data sets
what do box plots of data sets show?
- median
- lower quartile
- upper quartile
- inter-quartile range
what do error bars on graphical data indicate?
the range of data
when does correlation exist?
- if there is a relationship between two variables visible in data
- if the changes in the values of the independent variable are known to cause changes to the value of the dependent variable
what is correlation?
an association and does not imply causation
when does a positive correlation exist?
when an increase in one variable is accompanied by an increase in the other variable
when does a negative correlation exist?
when an increase in one variable is accompanied by a decrease in the other variable
