Unit 0 Flashcards
What are the 4 big ideas of biology?
Evolution, energetics, informational storage, system interactions
(EISSIE)
What does evolution explain?
How organisms are similar and how they are different from one another
What is one of the major mechanisms of evolution
Natural selection
What is energetics?
The dues that energy is required by all life forms to survive grow and reproduce and that organisms harness energy from the sun or from chemical compounds
What is the main ideas of information storage?
What are the main ideas of system interactions?
Interactions of the components of a system often result in emergent or new properties (not a change in a original component)
Cells organism and the biosphere are all systems that work in a coordinated fashion to sustain life
What do all experiments require?
Hypothesis, Independant, dependent, and constant variables, and control groups
What is a hypothesis?
Testable explanation of a phenomenon that’s capable of being tested and falsified by evidence
What are the two types of hypotheses
Alternate and null hypotheses
What is an Alternate hypothesis
Another way to say hypothesis that predicts that the treatment will have an effect on the outcome
What is a null hypothesis
predicts that the treatment will have no significant effect on the outcome and that any difference between the experimental and control groups is due to chance
Define theory
Explanation of how and why certain phenomena occur in the natural world base of observation experimentation and review. Not a fact and can be revised
Theory’s don’t become ____ with more evidence
Laws
Law definition
Describes what happens
Evolution is a theory or law
Theory
What’s the independent variable and where does it fall on graph
Variable that is manipulated or changed by the researcher. It will vary in experimental groups.
X axis
What’s the dependent variable and where does it fall on graph
The variable that changes in response to the independent variable and is being measured throughout the experiment
Y axis
What’s a constant variable
Variable that remains the same in every group of an experiment. It’s Essential to ensure that the changes in the dependent variable are being caused by the manipulation of the IV and not some other variable
What are the three experiments design groups?
Positive control group, negative control group, and test/experimental group
What is the positive control group and what’s it used for
Group that receives the normal amount/type of the independent variable
Used to ensure that the test subjects are working properly and to make comparisons
What is the negative control group and what’s its used for
Group that does not receive the IV
Used to ensure that the test subjects are working properly and to make comparisons
What is the test/experimental group and what’s it used for
Group that receives various amount/types of the IV that is different than control groups
Used to test hypothesis
All data points together are frequently referred to as _____
The experimental sample size
Why are experiments with more data better?
More data equals a bigger sample size which allows better statistical analysis This means it’s a better support for the conclusion drawn from the data
What are two types of data
Qualitative and quantitative
What is qualitative data
when is it not used
observations that cannot be numerically expressed
it’s not appropriate to use for science research because it’s not numerical and cannot be statistically analyzed
What is qualitative data
when is it used
Consists of discreet measurable units that are numerical expressed
Required for scientific research and can be statistically analyzed
What 2 things does a researcher require to know before analysis of data
Normalcy and the population as a whole
Normalcy is determined with a data set by calculating the ____ ____ ___ ____ ____
Mean, median, mode, range, standard deviation of the sample
MMMRS
Researchers can only do what after establishing normalcy?
Compare data points confirm trends, or patterns, and data and statistical analysis
What steps do you use to graph?
LUTES
label your axis
use the right graph type
title the graph
error bars, if applicable
scale your axis properly
When should you use a bar graph?
When the independent variable is sorted into experimental groups or categories
When should you use line graphs
When the independent variable is continuous and numerical
When should you connect the dots in a line graph?
If you’re trying to find the rate or overall trend, do not connect a dots use a line of best fit instead
What are error bars used for in graphs?
To compare and evaluate statistical significance of data points within a sample, and sample means between experimental group groups
True or false: the max values of the X and Y axis should end at your largest data point
False it should be greater than the largest data point
What’s the equation to find the scale of your graph?
What is the mean in a data set?
The average of values in a data set
The mean indicates what is considered ‘normal’ for the collected data.
What are the two basic types of mean?
- True Mean
- Sample Mean
What is necessary for statistical analysis of data for significance?
The mean must be calculated
True or False: You can draw statistical conclusions from just the mean by itself.
False
What is the true mean?
The average value of data taken from every member of a population
What is a sample mean?
The averages of data points in individual experimental groups used to compare averages between treatment types
How do you graph sample means and in order to do what
With air bars to determine if differences between treatment groups are statistically significant
What is a statistical test that quantifies the amount of variation in a data set?
Standard deviation
Standard deviation measures the dispersion of data points in a dataset.
What does standard deviation allow for in data comparison?
Comparison of data points WITHIN a sample to the mean
It helps to determine if a certain data point is statistically different than the average.
True or False: Standard deviation can be used to compare data points in different samples.
False
Standard deviation cannot be used to compare data points from different samples.
Do we typically graph standard deviation as error bars?
No
Standard deviation is usually not represented graphically as error bars.
What is the threshold for data points to be considered not significantly different than the mean?
Data points that fall between +/- 1 SD
SD stands for standard deviation.
What is considered significantly different than the mean?
Data points that fall outside of +1 - 2 SD
This indicates a greater deviation from the mean.
At what standard deviation is the mean located?
The mean is always at standard deviation = 0.
Image of example SD graph
What is variation
A measure of how spread out the data is around the center of the data
What is within group variation?
Variation within variables, not all the values with each group are the same
What is between group variation?
Variations among all variables
Another name for normal distribution of standard deviation graph is _____
Bell curve
What does SEM stand for?
Standard Error of the Mean
SEM is a statistical term that measures the accuracy with which a sample represents a population.
What is the relationship between SEM and sample size?
The smaller your SEM value, the more likely it is that your sample mean matches the true mean
A larger sample size typically results in a smaller SEM.
True or False: A larger SEM indicates a more accurate sample mean.
False
A larger SEM means less accuracy in representing the population mean.
Fill in the blank: The more data you have, the smaller your _______.
SEM
More data leads to a more precise estimate of the population mean.
What happens to the SEM as the sample size increases?
It decreases
A decrease in SEM indicates a better estimation of the population mean.
We use the SEM for ___
95% confidence interval
Regarding 95% intervals, Error bars represent ___
Range of values between which of the true mean could fall
(We can say with 95% confidence that the true mean falls within this range)
The 95% confidence interval is sometimes referred to as ____
+2SEM or -2SEM
How do you calculate the 95% confidence interval
Mean +2SEM for the top bar
Mean -2SEM for the bottom bar
What does it indicate if the bars do not overlap in a 95% confidence interval analysis?
The differences in the sample means are statistically significant
This means you can say with 95% confidence that the true means are not the same for the groups.
What does it indicate if the bars overlap in a 95% confidence interval analysis?
The differences in the sample means are NOT statistically significant
Overlapping bars means that it is possible for the true mean to be the same.
