In a preview post we was talking about the importance of a good information source. We also mentioned two information sources based on user panels, Alexa and Comscore.The main advantage is that comScore provide their Panel Users with software that measures lot of demographic information like gender, age, income, etc.
With the above mention information they project the data to the total internet data universe, using statistical procedures to correct potential deviation of information.
Like in the rest users panel there are certain limitations regarding the information accuracy. The best known is that sites with low level of traffic are not properly measured because the sample is lower than necessary to accurate an acceptable level of certainty.
Analyzing data accuracy
When using a panel like Comscore it is desirable having a constant relationship between the real data and the estimation it provide us.
In order to test this hypothesis we use the data from an important brazilian website.
As you can see in the following charts the estimations carried on by Comscore are significantly different from the real data. In some cases when the real increases in Comscore estimation it decreases and vice versa.
On the other hand the data from a panel of users tend to have a lower variability