Below the Surface

In this scenario, the model was mostly in shadow with a rim-light effect on his right side. The drawing below illustrates a true to life interpretation of how the model appeared. 

At the end of the drawing session, I was satisfied with the drawing in regards to the proportions and likeness of the sitter. However, the shading was too dark and gloomy for my liking. 

Before

The model was excited to be our subject of the day and had a lively personality. I felt that my drawing wasn't reflecting this aspect of the sitter. 

After

The correction (shown above), was to invent a fill light on the shadow side to clean out the heavy mood created by the excessively dark values. A few minutes spent lifting out the darks with a kneaded eraser transformed this entire drawing.  

By doing so, I was able to describe the forms of the face much better than in the first rendition and more importantly reveal the upbeat character of the model. 

I did do some minor finishes on his left shirt collar and better indicating on his ear but for the most part, this was a value adjustment. 

So, which version is correct? I'd say they both are. The "Before" for its "This is how it looks" honesty and the "After" for going beyond surface effect to reveal the sitter's personality.