Adrian Grenier

Actor Known for HBO's "Entourage"; Environmental Activist; UN Ambassador

Derek Hough

Dancer, NYT Bestselling Author, Emmy Award Winner for Outstanding Choreography & Six-Time Champion of ABC's "Dancing with the Stars"

Joy Behar

Comedian, Actress & Former Co-Host of "The View"

Kandi Burruss

Singer-Songwriter, Entrepreneur & Star of "The Real Housewives of Atlanta"

Ken Burns

Historian & Award-Winning Documentary Filmmaker

Cheryl Burke

Professional Ballroom Dancer, Model, TV Host, Known for "Dancing with the Stars"

Adam Carolla

Comedian, Entrepreneur and Host of "The Adam Carolla Radio Show"

Jussie Smollett

Actor and Singer Starring in Fox's, "Empire"

Aaron Koblin

Co-Founder & President at Supernatural & Within; Former Leader of the Data Arts Team at Google

Nick Carter

Member of the Pop Group The Backstreet Boys; Contestant on Dancing With The Stars Season 21

Nick Carter Reflects on Loss of Brother Aaron as He Returns to Music Career

Melissa Joan Hart

Writer, Television Director, Entrepreneur & Actress

Julianne Hough

Emmy Award Winner for Outstanding Choreography, Country Music Singer, Actress & Professional Dancer

Nick Cannon

TV Personality, Former Host of "Wild N Out" & "America's Got Talent"

Laurie Garrett

One of America's Premier Authorities on Healthcare and Disease Prevention

Lance Bass

Pop Singer & Dancer; Member of the Former Boy Band *NSYNC

Randy Jackson

Music Producer, Former "American Idol" Judge, Author & Health Advocate

Sara Evans

Country Singer-Songwriter

Mos Def

Hip-Hop Artist & Actor

Vanessa Carlton

Singer/Songwriter; Known for her hit "A Thousand Miles"

Jan Chipchase

Jan Chipcase can guess what's inside your bag and knows all about the secret contents of your refrigerator.

The Field Study Handbook, Field Edition