Comparing sentiment scores for posts about three British supermarket chains across December 2011.

1. Social Media Report:
Asda, Sainsburys, and Tesco December 2011.
Example Comparative Report.
Period: 01/12/2011 - 31/12/2011
The posts collected were divided into the following Tech classes:
Web
News
Blog
Microblogs
Media
Summary
Separate searches were set up for Asda, Sainsburys, and Tesco, and these ran for the whole
of December. The aim was to provide us with an experimental or example data set which we
could then use for testing our system. During December, the searches returned 106,070 posts
mentioning Asda, 51,192 mentioning Sainsburys, and 169,205 mentioning Tesco.
We used these three datasets to demonstrate the comparative sentiment analysis reporting we
have developed. A training set of 200 – 250 posts was classified by NTL, with three categories:
positive, negative, and int, or neutral. These training sets were used to create the classifier, and
then to classify the remaining data.
Graphs of average sentiment by time were produced for each supermarket chain across the
month, and for all three together.
© Churnbar 2012
http://churnbar.com enquiries@churnbar.com

2. 1600
pos
int
1400 neg
1200
1000
Frequency
800
600
400
200
0
-200
11/26/11 12/03/11 12/10/11 12/17/11 12/24/11 12/31/11 01/07/12
Month-Day
Asda sentiment by time (4 hour interval, volume of posts)
1200
pos
int
1000
neg
800
600
Frequency
400
200
0
-200
11/26/11 12/03/11 12/10/11 12/17/11 12/24/11 12/31/11 01/07/12
Month-Day
Sainsburys sentiment by time (4 hour interval, volume of posts)
© Churnbar 2012
http://churnbar.com enquiries@churnbar.com

3. 1800
pos
1600
int
neg
1400
1200
1000
Frequency
800
600
400
200
0
-200
11/26/11 12/03/11 12/10/11 12/17/11 12/24/11 12/31/11 01/07/12
Month-Day
Tesco sentiment by time (4 hour interval, volume of posts)
Commentary
These three charts show that there was a steady high level of posts throughout the study
period, fluctuating between a minimum at night and maximum during the day, for the int
(neutral) category, reflecting simple statements mentioning the chain. This obscures any
patterns of variation that there might be in the sentiment towards the grand, where it is shown,
so another method of demonstrating this is required.
0.5
Asda
Sainsburys
0.4 Tesco
0.3
0.2
Frequency
0.1
0
-0.1
-0.2
-0.3
11/26/11 12/03/11 12/10/11 12/17/11 12/24/11 12/31/11 01/07/12
Month-Day
Average sentiment of Supermarket posts.
© Churnbar 2012
http://churnbar.com enquiries@churnbar.com

4. Commentary
This chart was produced by calculating the average sentiment, where positive is +1 and
negative is -1, over each four hour period, and provides a better picture of the sentiment being
expressed about the three supermarket chains across December 2011.
While none of the three chains are mentioned with massively positive or negative sentiment,
the posts about Sainsburys are somewhat positive, those about Asda are neutral, and those
about Tesco tend towards the negative.
This pattern of sentiment towards the three supermarkets was confirmed by the fact that, over
December, Sainsburys saw year-on-year growth in volumes sold, while Tesco saw a decline,
which lead to them having their lowest share of the UK groceries market for some years.
This type of comparative analysis of sentiment can be used to highlight an issue before it
becomes a problem. By diving into the posts themselves, finding out what people were
complaining about and dealing with the issues, would it have been possible for Tesco to
rebound, or was the damage too ingrained? I’m sure that, had we produced this chart in late
December, it would have been possible to predict the results which were published in mid
January.
Could your company or brand benefit from this type of analysis?
© Churnbar 2012
http://churnbar.com enquiries@churnbar.com