Cards In This Deck

• $\text{Formula for the Product Moment Correlation Coefficient (}r\text{) using summary statistics?}$
  $r=\frac{S_{xy}}{\sqrt{S_{xx}{S}_{yy}}}$
• $$\begin{gathered} \text{True or False?} \\ \text{A strong correlation coefficient (}r\approx 1\text{ or }r\approx -1\text{) proves that a change in one variable causes a change in the other.} \end{gathered}$$
  $$\begin{gathered} \text{❌ False} \\ \text{Correlation does not imply causation.} \\ \text{There may be a third factor affecting both, or the relationship may be coincidental. You must use context and common sense to determine causation.} \end{gathered}$$
• $$\begin{gathered} \text{True or False?} \\ \text{If the Product Moment Correlation Coefficient (PMCC) }r\text{ is close to 0, there is no relationship between the variables.} \end{gathered}$$
  $$\begin{gathered} \text{❌ False} \\ \text{Correct reasoning: It means there is no LINEAR correlation. There could be a strong non-linear relationship (e.g., quadratic curve).} \end{gathered}$$
• $$\begin{gathered} \text{True or False?} \\ \text{A PMCC of }r\approx 0\text{ means the variables are completely unrelated.} \end{gathered}$$
  $$\begin{gathered} \text{❌ False} \\ \text{It means there is no LINEAR correlation.} \\ \text{There could still be a strong non-linear relationship (e.g., a quadratic curve).} \end{gathered}$$
• $$\begin{gathered} \text{True or False?} \\ \text{If variables are coded linearly (e.g., }x=\frac{u-10}{5}\text{), the Product Moment Correlation Coefficient (PMCC) }r\text{ changes.} \end{gathered}$$
  $$\begin{gathered} \text{❌ False} \\ \text{The PMCC }r\text{ is independent of linear coding.} \\ {r}_{xy}=r_{uv} \end{gathered}$$