Jennifer Roberts deftly moves her class at Point Loma High School in San Diego from a conversation about rhetoric discussing ethos, logos and pathos to a short video illustrating the terms through the story of a boy trying to get his mother to order a pizza for dinner. Roberts then directs students to complete a reading assignment on Chromebook laptops, so she can view their work online later and, over the course of the year, track their strengths, needs and progress.

There's a seamless transition between activities but also time for Roberts to check in with individual students and ask challenging questions.

Roberts' classroom is one of about 100 that Palo Alto High School English teacher David Cohen visited in California during a yearlong quest to find positive stories in public education. Starting in fall 2014, he observed teachers at more than 60 public schools -- small and large, rural and urban, affluent and poor -- who have been able to, as he describes it, "capture the spark" in their schools. He documented the trip in a recently self-published book, "Capturing the Spark: Inspired Teaching, Thriving Schools."

The "sparks," he said in an interview, "are the combinations of people, place and curriculum that excite students and teachers, that lead to innovation and deeper learning." It is the stories of these sparks that Cohen set out to capture himself, hoping to provide an "antidote" to what he describes as the prevailing negative narrative about public schools in California.

"The central argument of this book is that public education already has dedicated and talented people in place," Cohen writes, and taking note of these is key to the further improvement of public education.

The problems in California public education are well-documented, Cohen writes: schools labeled as "failures" by low standardized test scores, a wide achievement gap between students of color and their peers, inequities in school funding, an ongoing teacher shortage and top-down leadership that creates tension between teachers and administrations, among other challenges. While Cohen is under no illusions that these problems exist and require solutions, the classrooms he features in the book provide a balancing counternarrative, he said.

Many teachers Cohen set out to visit he knew personally or through his own professional network; others were recommended to him or had been recognized with state or national teaching awards.

At Newark Junior High School, where about half of the students qualify for free and/or reduced price lunches, Tom Collett's eighth-grade science class stands out for its combination of energy and firm expectations. Schoolwide, Cohen writes, efforts are underway to support students, from organizing a Special Olympics for special-needs students to sorting and organizing donated clothing on shelves and racks so impoverished students can experience a shopping-like experience.

Cohen believes future school reform depends on what he calls "best conditions" rather than replicating "best practices." Instead of imitating what has worked elsewhere, the right conditions from policies to working environments should allow schools to develop strategies that "are informed by others, yet based on their own strengths, which arise from their unique contexts," Cohen writes.

A metaphor in the book speaks to this concept: "Capturing the spark means not being distracted by the flames."

"The metaphor there was to suggest that when (great programs) ignite ... we need to make sure that the message isn't 'Everyone should do that' or 'Why don't you do that?' but instead say 'How did they get to a point where they pulled that off?'" Cohen said in an interview.

"It probably had something to do with the conditions rather than the specifics of any given program."

An example of that is offered locally, at Gunn High School. During his sabbatical, Cohen visited Ronen Habib's positive psychology course, which Habib developed in the wake of a student suicide. With the support of his administration, Habib designed the curriculum, sought approval from the University of California for course credit and launched a now-popular elective. The class combines activities like mindfulness and journaling with academic learning about concepts like happiness and self-esteem.

Many teachers in the book have also become instructional or policy leaders in some way (including Cohen himself, who has traveled to Sacramento and Washington, D.C. to lobby legislators on education issues and belongs to teacher leadership networks). Strategic development of teacher leadership, Cohen writes, is critical to the future of improvement in public education.

Other local examples of positive teaching abound in "Capturing the Spark," including in Cohen's home school district as well as in Mountain View, Atherton and Los Altos.

At Barron Park Elementary School, teacher Jennifer Harvey teaches the concept of "-ish," or "the acceptance of imperfection, of work in progress, giving ourselves permission to struggle with challenges, to attempt and revise without expecting perfection to come quickly or easily," Cohen writes.

At Alta Vista High School in Mountain View, a continuation school that serves Mountain View and Palo Alto school district students who struggled to find success at their more traditional high schools, teacher Marciano Gutierrez is highly attuned to the needs of his individual students.

"The energy level is a bit low, about what I'd expect from teens first thing in the morning, but Marciano is all revved up," Cohen writes. "He engages every student in the room and moves around constantly while reviewing the rise of the American labor movement following the Industrial Revolution."

Gutierrez isn't concerned when some students show up late, aware of which bus they rely on to get to school and what's going on at home, Cohen writes.

Many teachers Cohen describes in the book exemplify this combination of relationship building with academic rigor and high expectations as a means of "capturing the spark" with students.

Despite the book's optimistic perspective, Cohen, who has been a teacher for more than 20 years, is under no illusions that simply telling these stories translates into a plan for systemic educational reform.

"You would need to take this along with things you already know or can find out in other ways and hold them in a balance," he said. He's not suggesting people "ignore the negatives, but to come at them with perhaps a more strength-based approach and say, 'We have the potential to address those negatives by building on what we have rather than trying to scrap too many things and start over.'"

After the book came out, many teachers thanked him for what they felt was an "overdue" portrayal of public schools, he said.

"If it encourages people to make some connections or to think of something different that they might be able to talk about in their own school or district ... then I think that's at least a small, positive contribution," he said.