Unit 1 Test Flashcards
Things that change in a experiment
Variables
The actual thing that you are testing and changing across your experimental groups. On a graph, placed on the X-axis
Independent variables
The response to your independent variable changing, meaning measured or observed. On a graph, placed on the Y-axis
Dependent variables
Something that should be kept the same for the entire experiment, especially between different trials
The constant or controlled variable
The group that does not contain your independent variable, or the absence of what you’re experimenting. This is the see your independent variable actually causes a difference compared to when it didn’t exist. (in a control experiment, you only ever have one independent variable)
Controls
Designed where a known response is expected, for example, we expect bacteria to grow on nutrient agar
Positive control
Is designed where no responses are expected. This shows that your experimental set up is working properly. For example, we expect the antibiotics to kill bacteria grown on nutrient agar that has been sublimated with antibiotics.
Negative controls
That refers to the qualities of something (color, shape, texture, odor). An example would be the liquid turned orange after we added the iron.
Qualitative
That refers to the quantity of some thing (amount or value). An example would be the mass increased 4 g.
Quantitative
What are descriptive statistics?
Mean, median, standard error of the mean, and interquartile range (IQR)
What are the graphing requirements? (TALKS)
Title
Axis measurements
Labels with units
Key
Scale
What graph is used for comparing items?
Bar graphs
What graph is used for continuous independent variables? (Often use for change of time)
Line graphs
Hypothesis you write when saying independent variable does not have an effect on your dependent variable. Nothing is influencing your results.
Null hypothesis
Hypothesis you write when you say something influence your results (your independent variable). You disapprove the null and accept the alternative.
Alternative hypothesis
Represents the spread of your data from the mean/average.
Standard deviation
Represents how accurately your sample mean represents a population mean. (Comparing your sample to that of the world). When you graph the SEM, you always graph the SEM multiplied by 2. This represents 95% confidence interval.
SEM, standard error mean
Allows you to say either, we can reject the null hypothesis of no relation at the .05 level, or we have insufficient evidence to accept the at the .05 level.
Chi Square test
Is usually numerical, such as temperature and time. This usually depicted in a line graph. think rates.
Continuous data
Is categorical, and separate across different experimental groups. This is usually depicted in a bar graph.
Discrete data
X^2 represents
Chi-squared
