Because any piece of l (life outcome) data can have many different causes, it is extremely difficult ot directly connect life outcomes with specific personality traits. this key disadvantage for l data is referred to as:

Answer;

Multidetermination

Explanation;

-L Data is the information about an individuals personality based on their life record. The L data has several types of disadvantages, which includes;  

-It has limited behavioral information; for example, the informant is not with the person in question 24 hrs a day 7 days a wk so they cant no everything about them.

-There is lack of access to private experiences; It can't access inner thoughts emotions ones fantasies, fears, hopes and dreams etc but can be obtained via S data and some cases not at all.

-It is also more prone to error; when the informant talks about their friend in question especially since they remember unusual events in defining the persons personality as opposed to their daily day to day behaviors.