PIP face to face assesment

Thanks, I've heard aproximately 50% of assessment is visual observations. I've never had to have one for DLA nor ESA, I I've only had one in my lifetime which was 10 yrs ago...prob more, for incapacity benefit or income support can't remember, my forms have always included several pages of continued answers, letters from GP n psychiatrist, appointments at hospital, hospital discharge sheets etc,