Confidence interval: Confidence intervals provide a range for the expected relationship that accounts for miscalculations or change of circumstances. Narrow confidence intervals indicate high confidence in the expected relationship.

Critical thought: A count of reflective statements with substance. For example, "I agree with most said, but don't think it supports the conclusion" versus "Me too!"

Original contribution: A count of unique words used. X-Ray counts all words used in posts. It then removes the stop words. These are words that supplement the meaning, such as helping verbs, pronouns, and prepositions. The remaining words are then analyzed to determine original contribution. X-Ray counts the words and compares that number to how often those words repeat. Higher percentages for original contribution means less repetition and more unique words introduced.

Visit Regularity: This is how regular students are in their pattern of visiting the course.

Word Overlap: X-Ray compares all discussion posts and identifies the percentage of posts that contain overlapping parts, such as sentences that are identical between posts.