When examining a bar graph of an interaction effect, what characterizes a spreading interaction?

A researcher creates a bar graph to display the results of a 2 × 2 factorial experiment. At the first level of the variable on the horizontal axis, the two bars are nearly identical in height. At the second level, one bar is substantially taller than the other. This pattern is best described as a cross-over interaction.

A researcher is analyzing a bar graph for a $2 \times 2$ factorial design. At the first level of the horizontal axis variable, the two comparison bars are of equal height. At the second level, however, the height difference between the bars is large and prominent. By evaluating how the relationship between these bars changes in magnitude across the two levels without a reversal in direction, the researcher identifies the presence of a(n) ________ interaction.

An undergraduate researcher is evaluating various visual data patterns from a $2 \times 2$$ factorial design to determine which outcome most definitively supports a 'spreading interaction' hypothesis compared to a 'cross-over interaction'. Arrange the following bar graph descriptions in order from the most definitive evidence of a spreading interaction to the most definitive evidence of a cross-over interaction.

Based on visual patterns in bar graphs for a $2 \times 2$ factorial design, match each interaction term with its corresponding description.

Match each research finding with the bar-graph interaction pattern it would produce, assuming the first variable mentioned is on the horizontal axis and the second is represented by the bar colors. (Each pattern label may be used more than once.)

A researcher runs a 2×2 factorial experiment and displays the results in a bar graph. Match each description of the bar graph's visual pattern to the correct term.

A psychology researcher conducts a 2×2 factorial study examining the effects of study method (spaced vs. massed practice) and sleep quality (good vs. poor) on exam performance. The bar graph shows that students with good sleep score substantially higher with spaced practice than with massed practice, whereas students with poor sleep score nearly the same regardless of study method. Which type of interaction does this bar graph depict?

A researcher analyzes a bar graph from a 2×2 factorial design and observes that at Level 1 of the horizontal-axis variable, the bar for Condition B1 is substantially taller than the bar for Condition B2, while at Level 2 the bar for Condition B1 is only slightly taller than the bar for Condition B2. Because a height difference between B1 and B2 is visible at both levels, the researcher concludes that the graph displays a cross-over interaction.

A researcher presents the following findings to a peer review panel: 'At Level 1 of Variable A, participants in Condition B1 scored 30 points higher than participants in Condition B2. At Level 2 of Variable A, participants in Condition B2 scored 25 points higher than participants in Condition B1.' A panel member evaluating the strength of this finding concludes that the bar graph for these data would display a _____ interaction—the type considered the most compelling evidence that the effect of one variable is fully reversed, not merely reduced, by the level of the other variable.

Based on the visual representation of interaction effects in bar graphs, define the terms 'spreading interaction' and 'cross-over interaction' by describing the specific visual patterns of bar heights that characterize each type.

Evaluate the research team's interpretation of their bar graph. Explain why their label is correct or incorrect, and describe the correct interaction pattern shown in their graph based on the relative bar heights across both levels of task complexity.

Suppose a researcher expects a spreading interaction in a $2 \times 2$ factorial experiment where independent variable A (levels A1 and A2) is on the horizontal axis and variable B (levels B1 and B2) is represented by bar colors. If there is a large difference in scores between B1 and B2 at level A1, describe what the comparison bars (B1 vs. B2) must look like at level A2 to support their hypothesis.