What is a procedure?
an organized and numbered list of steps that explain how to do an experiment
Developing Well-Written Procedures
- use a numbered list of steps
- organize the steps in the order you would do them in a lab
- avoid using pronouns (I, you, we, he, she, it, etc.)
- use commands (list, pour, add, measure, weigh)
- tell the reader to measure and record data when it is appropriate
- explain what data to record and how to measure this data
- refer to measurements used on the metric system (mm, cm, m, mL, g, etc.)
- eliminate unimportant information
- sketch and label the experiment set-up. refer to sketches in your procedure. if you need multiple sketches, number them starting with 1. refer to each sketch by number in the procedure.
- include all steps. no matter how small the step seems, it may be the critical step for a researcher to replicate the procedure
- tell when it is necessary to repeat one or more steps in the procedure
What is a hypothesis?
- an educated guess
- prediction
- done before the experiment
- can be wrong
- thinking about a problem/question
should be... • clearly written • reasonable/realistic • "if/then" format • based on research & general knowledge
Example:
IF I add 2 mg more salt to my flubber,
THEN I think it will become more dry and less flexible
What is the control?
- the variable that stays the same
- the constant
- doesn’t change
What is the dependent variable?
• the variable that you are measuring
What is the independent variable?
- the input variable
* the variable that you change
What is TALKS?
acronym to help you to remember the parts of a graph
T - Title (above graph) A - Axes (x & y) L - Label (x = IV, y = DV) K - Key (identifies meaning for each color or symbol) S - Scale
What are pie graphs?
Pie Graphs
- percents of population
- percents of abundance
- must add to 100%
- use only for data that add to a meaningful total
- don’t compare between two pie charts
What are bar graphs?
Bar Graphs
- abundance/quality of comparison data
- categorical data
- area of bars can imply volume
- categorical names with long x-axis can be moved to the y-axis
- you can switch axes for convenience/space
What are scatter graphs?
Scatter Graphs
- numerical data (both axes)
- two or more variables
- look for patterns
- best-fit line (trendline) can be used to show trends
- only extend line to axis if it’s meaningful
What are line graphs?
Line Graphs
- all data points are connected in a sequence
- the line connecting the points is not based on statics or patterns, but chronology
- connect points with a line
- can be used for categorical data
What is a conclusion?
a conclusion tells what the lab was about and summarizes it
Model:
The purpose of this lab was (tell what the purpose was). What we did during the lab was (describe the procedure in 1-2 sentences). My hypothesis was (tell what your hypothesis was). My hypothesis was (correct or wrong) because (explain why it was correct or wrong). The results of the lab were (explain what the results were, include actual data). The errors from the lab were (explain what the errors were, if there were none, state there were no errors). I could have improved the lab by (explain what you could have done to do a better job on the lab). From this lab, I learned (explain what you learned from this lab).
