Lab #1 Review - Experimental Design & Metric Systrm

Notes and topics from lab #1 to review for exam

Standard Error Equation

SE = s/square root(n)

s = standard deviation, n = sample size

Scatterplot

Line graph

Bar graph

Histogram

Used to display data in categories, spaces between bars

Verticle touching bars, used for data that continously

Don’t forget title and to label axis when creating graph

Surface Area equation (cm²)

SA = 2(lw +lh +wh)

l = length

w = width

h = height

Volume equation (cm³)

V = lwh

Quantitative traits

Are controlled by multiple genes, represented by a bell/normal curve

Mass & Volume relationship of water

1g=1cm³=1mL

Independent Variables (treatment variables)

Variables that you manipulate

Experimental group

Category of treatment of independent variables: a group that has been subjected to a hypothesized casual factor

Control Group

Category of treatment of independent variables: group that has the “baseline” condition, providing a comparison to experimental groups, to asses the effect of treatment

Potentially Confounding Variables

Other variables that are held constant between groups

Dependent variables (outcome variable)

Appropriate measures of the treatment’s effect

Scope of inference

Applicability of the results, global or specific circumstances, to increase ___ replication is key

Replicate

helps to demonstrate a general pattern, applying treatment to multiple experimental units (each experimental unit is one ____)

Assign experimental units randomly to groups (experimental or control group), i.e. don’t put all the A students in the same group

How to increase confidence of results?

Systematic variation - Conditions that may influence results outside of experiment

Scope of inference — individuals are inherently variable, cannot assume because something works for one person that it will work for another

Types of Logical errors: (2)

Experimental Units

is the subject of treatment in an experiment. In biology, _____can be cells, individual organisms, populations, or whole communities.

Hypothesis

It proposes an explanation for a pattern. The hypothesis must make clear the evidence that would support or disprove that explanation.

good ___ must be falsifiable — you should be able to show that the hypothesis is wrong with some sort of test

Casual Factor

specific variable that directly influences the outcome, meaning changes in the _____ directly lead to changes in the effect.