In this study 100 groups of five participants were used to discover problems with an interface. The study did indeed find that the mean percentage of problems discovered across all 100 groups was about 85%. However, this figure has 95% confidence level and a margin of error of Â±18.5%.
Keelboats were generally built in Pittsburgh, Pennsylvania and it was here that Meriwether Lewis commissioned the boat used by the Corps of Discovery. The keelboat used by the Corps was sketched by Clark in his journal. It was 55 feet long and 8 feet wide, with a 3- to 4-foot draft. For propulsion it had a 32-foot sailing mast, 22 oars, a rudder, and a tiller for steering. Protection against hostile encounters were a swivel cannon on the bow and two smaller guns called blunderbusses.
Double up the fun! Polyethylene roto-molded for strength and durability. The Splash II Kayak features full length keels for strait tracking to make it easier to stay on course for longer paddling. The splash Kayaks were designed by olympian and kayak design guru Bob McDonough to be fun boats for everyone. Great for paddling in oceans, lakes, bays, and almost anywhere you find water. Length 12', Width 32. Weight Limit 500 lbs. Double kayak comes with 2 Paddles and 2 Life Vests.