Stats Flashcards
Data definition
Recorded observations
Types of data
qualitative and quantitative
Qualitative data
descriptions, value cannot be 0, pictures, words
Quantitative data
recorded measurements, can have a value of 0, NUMBERS
Hypothesis definition
a proposition, is testable and should be falsifiable, makes predictions, never really proven, made based on observations
Theory definition
broad explanation, backed by lots of evidence, a theory gives us the ability to make predictions, can almost treat them like a fact
Hypothesis testing steps
observations, hypothesis formation, experimentation, data analysis, conclusion
Discovery based science
collection and analysis of data without the need for a preconceived hypothesis, goal is to gather more info. Ex: test drugs to look for action against a disease
Control group
not subjected to one specific variable, participants who do not receive the experimental treatment
Experimental group
what you are changing (purpose of the experiment), subjected to some type of variation that does not occur in control group
Independent variable
What you are changing in your experiment, should influence the dependent variable
Dependent variable
The variable of interest, affected income
Scientific method steps
observations, hypothesis formation, experimentation, data analysis, conclusion
Population
entire set of items that you are interested in
Sample
Portion of population
Null hypothesis
proposes that NO statistical significance exists among a given set of observations ex: fertilizer does no affect plant growth
-null = no difference
Alternative hypothesis
proposes there is a statistical significance among a given set of observations ex: fertilizers really does cause a change in plant growth
Standard deviation
the dispersion of values from the average or mean, how spread out the data is, larger standard deviation means data is more spread out, lower is data is more clustered around mean
Student T-Test
Tells you how significant the differences between group means are (does data from sample go to the whole population)
What do you need to do a Student T-Test
-To do a T-test you need the mean, standard deviation and N (sample number for each group)
P-value
how valid are my results, p value should be LESS than 0.05 to be valid, it means that you are 95% positive that the two groups are statistically different, means if you repeated the experiment, you would be likely to get the same results
Statistically significant
if experiment was repeated, would you get the same result
