Answer to Question 1
Answer:
A correlation is a statistical indication of how strongly two variables are related. A correlation between two variables can range from -1.0 to +1.0. A correlation of 0 indicates that there is no relationship between two variables, while a correlation closer to -1.0 or +1.0 indicates a stronger relationship. More specifically, a positive correlation (greater than 0) indicates that, as values for one variable increase, so do values for the other variable. A negative correlation (less than 0) indicates that as values for one variable increase values for the other variable decrease. So, for example, attractiveness is positively correlated with dating activity (as attractiveness levels increase, people tend to date more), while football-team errors are negatively correlated with winning (as numbers of errors (interceptions, fumbled tackles) increase, the ratio of wins to losses decreases. Although extremely useful for making predictions, correlations by themselves cannot be used as indicators of causality (although it is tempting to make a causal connection between mistakes on the football field and losing football games).
Answer to Question 2
Answer:
Systematic observation involves carefully observing and measuring behavior as it occurs. Systematic observation may take place in any setting. One goal of systematic observation is to obtain an accurate measure of behavior. Naturalistic observation involves the application of systematic observation to natural settings such as playgrounds, parks, malls, private homes, etc. One goal of naturalistic observation is for the researcher to remain as unobtrusive as possible so as to not influence the behavior he or she is observing.
Examples of the results of sexual selection, a type of natural selection.
Examples of plant movements.
Scatterplots of Variables Having Several Different Levels of Correlation
Examples of X-linked Immunodeficiencies
Examples of Nasal Drops
Examples of Disease-Causes Bacteria