Diary Study is more of a qualitative study and is conducted over a long period of time by placing a “diary” in consumers’ homes. The consumers are then requested to record their observations, experiences while using the product, their activities (what to record is determined by the area of interest).

When to use: Diary Study is a very effective tool used to determine in-home consumption patterns of consumables such as food items, home care items etc. this tool can be used to determine habits, usage patterns, purchase patterns, any changes in consumers’ behaviours. For example, if one were to observe the consumers’ interaction with Cooking Oil. We will place the diary and ask the consumers to note following:

  1. Quantity used every time they cook a meal
  2. What price they bought at
  3. What quantity was bought
  4. From where did they buy
  5. Do they use different oils for different foods

The study is effective only if it is done for a longer period.


  1. Gives a good understanding on consumers’ interaction with a particular brand or household item
  2. We can study multiple categories at the same time


  1. Since it is self-reported study, the behavior is mostly claimed
  2. Consumer may or may not fill the diary immediately and hence may fill diary based on what they may recall. This sometimes may lead to inaccurate data


  1. Panelists need to be trained well before the study is initiated