PS102 Lecture Notes - Lecture 4: Optic Nerve, Null Hypothesis, Statistical Significance
Strength of a Correlation
● The positive or negative sign reflects direction not strength
● 0 to 1 = positive and -1 to 0 = negative
● So which is the stronger correlation
● .3, -.8, -.2, .7 → -.8 is stronger
Reading Correlation Graphs
● Data points
● Scatterplots
● Line of best fit
● Angle of line reflects correlation
Why Correlation Studies?
● Because you can have access to two pieces of information but may not be able to
manipulate the variables
● First step in the inferential process
Inferential Statistics
● Used to test hypotheses
● Lots of different tests selected on the basis of the characteristics of the study (compares
mean scores)
● E.g. t-test, f-test, etc
● Try to determine if the results are due to chance or not (null hypothesis)
● Probability statistic “p”
● p<.05
● Statistical significance: significant or not significant
○ States whether reliable, not “important”
Sensation and Perception
● Sensation is the process through which the senses detect visual, auditory, and other
sensory stimuli and transmit them to the brain
● Perception is the process by which sensory information is actively organized and
interpreted by the brain
● Example: blind spot - where the optic nerve is (no photoreceptors there)
● Sensation gives us the visual cues
● Perception fills in the blanks
● Sensory Transduction: converting information in environment into neural impulses
What can we Sense?
● How much stimulation has to be out there before we can detect that it is there? →
Thresholds (we have two kinds of thresholds)
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
The positive or negative sign reflects direction not strength. 0 to 1 = positive and -1 to 0 = negative. 3, -. 8, -. 2, . 7 -. 8 is stronger. Because you can have access to two pieces of information but may not be able to manipulate the variables. Lots of different tests selected on the basis of the characteristics of the study (compares mean scores) Try to determine if the results are due to chance or not (null hypothesis) Sensation is the process through which the senses detect visual, auditory, and other sensory stimuli and transmit them to the brain. Perception is the process by which sensory information is actively organized and interpreted by the brain. Example: blind spot - where the optic nerve is (no photoreceptors there) Sensory transduction: converting information in environment into neural impulses. The difference between not being able to perceive a stimulus and being able to just barely perceive it.
