What would you put effort in this matrix-learning?
Given two dimensions, time and target, forming the following learning-matrix, what would you put (anything related about being a developer) in the following four regions?

                  limited time     continuous<br/>
with target            1               2<br/>      

without target         3               4<br/>


for example, below is my trial: 
1. certification<br/>
2. API / framework<br/>
3. language syntax<br/>
4. principle / theory<br/>

What would you put effort in this matrix-learning?
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Given two dimensions, time and target, forming the following learning-matrix, what would you put (anything related about being a developer) in the following four regions?

                  limited time     continuous<br/>
with target            1               2<br/>      

without target         3               4<br/>


for example, below is my trial: 
1. certification<br/>
2. API / framework<br/>
3. language syntax<br/>
4. principle / theory<br/>
