Is this for your half training or your 10K? Your half pace will be slower than your 10K, but my take is, especially in the summer with warmer temps (which are going to force you to slow down) is just to run the interval sections faster than your easy portions--what this is doing is allowing your body to dip into the glycogen stores so that you build more and bigger glycogen tanks, whereas the easy portions are teaching your body to utilize fat for fuel.
ACE Certified Personal Trainer, RRCA Certified Running Coach
Member of the NTX Runners, DRC, Rockwall Running Club, Plano Pacers, NYRR, Team Runnersconnect
"No weight is ever PERFECT enough to do the enormous job of CREATING happiness!" From The Don't Diet, Live-it Workbook