15.071 | Spring 2017 | Graduate

The Analytics Edge

5.2 Turning Tweets into Knowledge: An Introduction to Text Analytics

5.2 Turning Tweets into Knowledge: An Introduction to Text Analytics

Quick Question

For each tweet, we computed an overall score by averaging all five scores assigned by the Amazon Mechanical Turk workers. However, Amazon Mechanical Turk workers might make significant mistakes when labeling a tweet. The mean could be highly affected by this.

Which of the three alternative metrics below would best capture the typical opinion of the five Amazon Mechanical Turk workers, would be less affected by mistakes, and is well-defined regardless of the five labels?

Explanation The correct answer is the first one - the median would capture the typical opinion of the workers and tends to be less affected by significant mistakes. The majority score might not have given a score to all tweets because they might not all have a majority score (consider a tweet with scores 0, 0, 1, 1, and 2). The minimum score does not necessarily capture the typical opinion and could be highly affected by mistakes (consider a tweet with scores -2, 1, 1, 1, 1).

Course Info

As Taught In
Spring 2017
Level
Learning Resource Types
Lecture Videos
Lecture Notes
Problem Sets with Solutions