The best espresso this side of Milan, or is it? Focus group experiment - Graphs and analysis of results

Potential flaws with the experiment:

• The people who took part in the focus group are NOT coffee experts,simply regular customers to Cafes in Durham City. However, this could be seen as a benefit as it is a true reflection of regular customers to Caffe Nero, they are marketing towards regular people and not coffee experts. 
• All participants are of a similar age: 20/21. This may present an age bias in the results. However this is hugely useful for a young target audience.
• The two taste tests did not occur in a short space of time. However this may have given the participants plenty of time to judge Caffe Nero without subconsciously comparing it to Milan.