Even if you get the right amount of sleep each night, there is a good chance you aren’t getting the quality of sleep you need to feel alert and energetic. In a new study published in the journal Frontiers in Sleep, Harvard researchers surveyed over 1,000 adults, asking them to rate their sleep based on a number of factors that reflected how restorative that sleep was. These questions included whether the person felt grouchy, felt energetic, or was in a good mood. They used these answers to calculate a total sleep quality score for each person. Less than 30 percent of people in the study had high scores considered to indicate restorative sleep. Based on their data, the researchers believe that if you don’t feel great after a night’s sleep, you should look back at the night before and try to figure out how you can sleep better the next night.