Changes

* A variable that depends on previous values of this same variable is not independent and is called auto-correlative? and non-stationary. For example skills at playing the guitar.

* A variable that depends on previous values of this same variable is not independent and is called auto-correlative? and non-stationary. For example skills at playing the guitar.

* Randomness of Missingness. Similar to independence but its not the value of the variable but whether other measured variables could correlate with higher incidence of missing values. For example forgetting to charge the smart band because of tiredness and having a night without it on.

* Randomness of Missingness. Similar to independence but its not the value of the variable but whether other measured variables could correlate with higher incidence of missing values. For example forgetting to charge the smart band because of tiredness and having a night without it on.

* Target. Level. Is this variable something you want to improve, or a variable likely to affect those or just an intermediary background variable measured because it was easy and provided context?

* Target. Level. Is this variable something you want to improve, or a variable likely to affect those, or just an intermediary background variable measured because it was easy and provided context? If this is a target variable, mention the purpose of of tracking such as [[Longevity]], your doctor told you based on [[Lab tests]], or are you trying to improve performance [[Sports]].

* Similarity. Proxy. Is this variable measuring something very similar to what another variable is measuring. The most common example is [[Tools for heart rate or pulse|heart rate]] as many wearable measure it and the avid self tracker always has a few.

* Similarity. Proxy. Is this variable measuring something very similar to what another variable is measuring. The most common example is [[Tools for heart rate or pulse|heart rate]] as many wearable measure it and the avid self tracker always has a few.

* Sign. Positivity. If variable is a target, are higher values better or the opposite. Sometimes some middle value is best like with BMI.

* Sign. Positivity. If variable is a target, are higher values better or the opposite. Sometimes some middle value is best like with BMI.