Title placeholders for custom post types

functions.php

<?php

// Change placeholder text for  post titles
add_filter( 'enter_title_here', 'my_title_placeholders' );

function my_title_placeholders( $placeholder ){
    $screen = get_current_screen();
	switch ( $screen->post_type ) {
		case 'people':
			$placeholder = __( 'Enter full name' );
			break;
		case 'course':
			$placeholder = __( 'Enter course title' );
			break;
		case 'facility':
			$placeholder = __( 'Enter building name and number' );
			break;
		case 'research':
			$placeholder = __( 'Enter research project title' );
			break;
		case 'publication':
			$placeholder = __( 'Enter publication title' );
			break;
		default: break;
		
	}

    return $placeholder;
}