Author resource box

Unless you’re doing something extra complex, just have each author put their miniature biography in the “About Yourself” box. That way, the information can be edited inside WP, instead of manually editing a PHP file.

Please take a look at the Author Template Tags and see if using a combination of those can do what you want.

Instead of separate files, can all this be done with conditional statements in the single.php template file?

if (get_the_author_nickname() == "saralex") {
 // do something
} elseif (get_the_author_nickname() == "Another Name") {
 // do something else
} else {
 // when all else fails, do the default
}

Consider taking a look at this tutorial: PHP Easy PHP Tutorial for WordPress Users

Other notes:
-WordPress template tags that begin with “the_” generally output (print) the information. Template tags that begin with “get_” usually return the information for use inside a function.

-In PHP coding, a semi-colon (“;“) is used to denote the end of a line of code. Using it inside a function such as include() will cause errors.

Now, if you were to include a file like you originally wanted, your best bet would be to use something like the following:

<?php include( get_bloginfo('wpurl') . '/wp-content/my-includes/' . get_the_author_ID() . '.php' ); ?> where get_the_author_ID returns the user ID (a number) for the author.