Lecture 1 + 2 Flashcards
hypothesis
a testable statement; falsifiable
controlled variables
ideally don’t change, common to all treatments
independent variables
what you are altering in the experiment
dependent variable
what you are observing in the experiment; respond to changes in independent variable
positive controls
an experimental treatment which will give the desired result
negative controls
an experimental treatment which will not give desired results
false positive
- shown by negative control
- something wrong with machine/sample
false negative
shown by positive control
single blind
one knows
double blind
both don’t know
causation
A caused B
correlation
A + B, but there could be a C that affected things
sensitivity
min. amount of X needed to record a positive result
specificity
a positive result only comes from a truly positive sample
random error
new error introduced with each measure (weather, temp)
systematic error
error that is consistently present (machine)
accuracy
how close to true value
precision
how reliable; comparing to other measurements
Realistically, any lab manipulations with have…………sig figs
2, maybe 3
pH meter
- glass probe permeable to H+
- current by probe compared against standards to report a pH value
scale
- to weigh chemicals
- must be tared/zeroed with empty container
volumetric pipette
measure just one volume
graduated pipette
lines along length
some pipettes are ______, some arent
blow out
