Are teachers' impacts on students' test scores ("value-added") a good measure of their quality? This question has sparked debate partly because of a lack of evidence on whether high value-added (VA) ...

Download this Measuring Charts With 10 25 Centimeters Templates Rulers Scales Set Length Measurement Math Distance Height Sewing Tools vector illustration now. And search more of iStock's library of ...

Companies measure the success of transactional emails by looking at metrics like opens, clicks, and delivery rate. Check out findings from this email study.