How do you read a lift?

How do you read a lift?

Lift is simply the ratio of these values: target response divided by average response. For example, suppose a population has an average response rate of 5%, but a certain model (or rule) has identified a segment with a response rate of 20%. Then that segment would have a lift of 4.0 (20%/5%).

How do you interpret incidence odds ratio?

In general:

1. If the risk ratio is 1 (or close to 1), it suggests no difference or little difference in risk (incidence in each group is the same).
2. A risk ratio > 1 suggests an increased risk of that outcome in the exposed group.
3. A risk ratio < 1 suggests a reduced risk in the exposed group.

How is the odds ratio similar to lift?

The odds ratio is not as intuitive, but similar in concept to lift. It is the ratio of the odds of X to the odds of Y. Restated, the odds of X is 10.09 times greater than the odds of Y. People generally readily understand lift, so use that whenever possible.

How is the strength of the Association determined?

The magnitude of the odds ratio is called the “strength of the association.” The further away an odds ratio is from 1.0, the more likely it is that the relationship between the exposure and the disease is causal. For example, an odds ratio of 1.2 is above 1.0, but is not a strong association. An odds ratio of 10 suggests a stronger association.

What’s the meaning of lift in association rules?

Lift is a very literal term given to this measure. Think of it as the *lift* that {X} provides to our confidence for having {Y} on the cart. To rephrase, lift is the rise in probability of having {Y} on the cart with the knowledge of {X} being present over the probability of having {Y} on the cart without any knowledge about presence of {X}.

What does a lift ratio of 1.25 mean?

To calculate the lift ratio, we divide the confidence ratio by support of consequent. That would be 75%/60% = 1.25. It is generally considered that lift ratios higher than 1 indicate strong association between items. Lift ratios below 1 mean that the items are not likely to be bought together.