Dear Anna Roberts,

Clearly, the interpretation of  y- intercept , the value at which the fitted line crosses the y-axis looks simple, but at times, it may run into confusion. When subs(x) is 0, this situation is commonly expected. In this situation, you cannot expect a relationship identified on the targeted data over a limited range to be appropriate any where, and as a result, you should be cautious about putting and real meaning on the fitted value at zero. Probably, you did something wrong, for instance, you violated certain assumptions(e.g., presence of outliers). I refer you back to two valuable sources by Jim Frost, (2013) and Peter Flom (2014).

Best regardsm

R. Biria

thank you Reza

Dear Ms. Anna Roberts,

I do apologize for the wrong answer to your question. However , I refer you to a book titled "reasoning test and mother skills" by Abel (2012). I hope it might help.

Best regards,

R. Biria

no worries Reza - thank you for suggesting the book.

Dear Anna,

I think everything depends on a certain language. Please, google the keywords "mother tongue influence", "test results" ,and so on, and you will find many interesting works (for ex., "http://jeteraps.scholarlinkresearch.com/articles/Effect%20of%20Mother%20Tongue.pdf).