This document describes the BakeAgain project which aims to improve recipes by analyzing user comments. It uses natural language processing and machine learning techniques like Gaussian Naive Bayes and TF-IDF to classify words in comments and determine comment sentiment. By identifying words related to modifications and ingredients, it seeks to determine which changes users suggest improve recipes based on 2,000 to 9,000 comments per recipe. The goal is to encourage more people to bake by further refining recipes.

1. BakeAgain
Helen Craig
Insight Data Science Fellow
2015
To improve one’s recipes and encourage people
to bake again.

3. Algorithm
natural language
processing
Gaussian Naive Bayes:
modifications from comments
TF-IDF + Multinomial Naive Bayes:
Comment trending topics
BakeAgain
2k-9k comments per recipes

4. Algorithm
natural language
processing
Gaussian Naive Bayes:
modifications from comments
TF-IDF + Multinomial Naive Bayes:
Comment trending topics
compare recipe reviews to
movie reviews
movie review: ‘wonderful/terrible’
food review: ‘chewy/mushy’
BakeAgain
2k-9k comments per recipes

5. The Data
“I did as suggested in other reviews
and increased the flour by 1/2 cup
and baking soda by 1/2 tablespoon,
cut the salt to 1/2 tsp. This made the
absolutely best cookies ever!! I made
them this afternoon thinking they'd
last the rest of the week. No way!
Between my husband and two
children, they'll be gone by tomorrow
night. They're fantastic. I'll make
these alot!”

6. The Data
“I did as suggested in other reviews
and increased the flour by 1/2 cup
and baking soda by 1/2 tablespoon,
cut the salt to 1/2 tsp. This made the
absolutely best cookies ever!! I made
them this afternoon thinking they'd
last the rest of the week. No way!
Between my husband and two
children, they'll be gone by tomorrow
night. They're fantastic. I'll make
these alot!”
The Complication
“I added 1 teaspoon salt.”
Original Amount:
2 teaspoons

7. Action Words used with Salt in Chewy Chocolate Chip Oatmeal Cookies
“Add”
“Use”
“Instead of”
“Decrease”
Decrease Salt
"I also added less salt than it called for, about
1/4 teaspoon."
"I also only used 1/4 t salt since I always use
margarine."
"For those complaining it's too salty-try 1/2 tsp
salt instead of 1 tsp salt."
"My only suggestion is, if you are using salted
butter, be sure to omit the extra salt."
“Increase”

8. Gaussian Naive Bayes fit
Word Use Frequencies in Comments
Decrease Butter Increase Flour Add Walnuts
“Use”
“Instead of”
“Decrease”
“Add”
“Add”
“Increase”
accuracy 70%-80%
5 (by hand) tagged recipes
leave one out cross validation
2k-9k comments per recipes

9. Helen
Craig

10. screen shots

14. backup

15. reduce modification-
related words
Algorithm
classify ingredients-
related/modification-related
words and adjectives
Find ngrams with
classified words
Gaussian Naive Bayes to
decide overall meaning in
comments:
add, inc, dec, mix
half
remove
omit
decrease
‘use walnuts’
‘reduce salt’
Multinomial
Naive Bayes:
Food Description

16. Other classifiers
K Nearest Neighbors
Linear SVM
RBF SVM
Decision Tree--reasonable
Random Forest--reasonable
AdaBoost--reasonable
Linear Discriminant Analysis--good
Quadratic Discriminant Analysis--good

17. Taking the sentiment out of sentiment analysis
pos review: ‘wonderful’
neg review: ‘terrible’
movie review: ‘wonderful/terrible’
pos review: ‘chewy’
neg review: ‘mushy’
movie
negative
positive
TF-IDF +
Multinomial Naive Bayes

18. to-do
Reviews that mention other reviews
word2vec to find more action words
modifications vs. ratings