It's been a trend for several years: fewer children's picture books on retailers' shelves. Publishers say part of the reason is that parents are pushing kids towards chapter books sooner. Kathy Hirsh-Pasek, a developmental psychologist at Temple, has noticed the trend, too. "It's really important to have books and it's really important to read to our children, but it's not really important to rush them ahead too quickly," she said. According to Hirsh-Pasek, picture books make it easier to get into conversations about a story: "Engaging in dialogic reading helps children learn about words and stories and builds literacy."