" However, the observer pattern can be used to provide some indirection between model and view, allowing the model to notify interested parties of a change. A view object can register itself with the model and listen for changes but the model itself remains view-agnostic . The controller does not pass domain objects (the model) to the view although it might issue a command telling the view to update itself. The user interface waits for further user interactions, which begins the cycle anew. Benefits and liabilities Although widely used, MVC has both advantages and disadvantages compared to other design options, and individual circumstances should be used to choose the most appropriate design. We discuss some of those here. View instability vs. Home Log Model model stability If constructed correctly, models can enjoy a fair degree of stability (owing to the stability of the domain model), whereas user interface code usually undergoes frequent and sometimes dramatic change (typically because of usability problems, the need to support growing classes of users, or simply the need to keep the application looking "fresh"). Separating the view from the model makes the model more robust, because the developer is less likely to "break" the model while reworking the view. "

" Table Left handed fermions in the Standard Model Fermion (Left-handed) Symbol Electric charge Weak charge* Weak isospin Hypercharge Color charge* Mass** Generation 1 Electron e -1 2 -1/2 -1/2 1 0. 511 MeV Electron neutrino νe 0 2 +1/2 -1/2 1 < 50 eV Positron ec 1 1 0 1 1 0. 511 MeV Electron antineutrino 0 1 0 0 1 < 50 eV Up quark u +2/3 2 +1/2 +1/6 3 ~5 MeV *** Down quark d -1/3 2 -1/2 +1/6 3 ~10 MeV *** Anti-up antiquark uc -2/3 1 0 -2/3 ~5 MeV *** Anti-down antiquark dc +1/3 1 0 +1/3 ~10 MeV *** Generation 2 Muon μ -1 2 -1/2 -1/2 1 105. 6 MeV Muon neutrino νμ 0 2 +1/2 -1/2 1 < 0. 5 MeV Anti-Muon μc 1 1 0 1 1 105. 6 MeV Muon antineutrino 0 1 0 0 1 < 0. 5 MeV Charm quark c +2/3 2 +1/2 +1/6 3 ~1. Design Home Interior Model5 GeV Strange quark s -1/3 2 -1/2 +1/6 3 ~100 MeV Anti-charm antiquark cc -2/3 1 0 -2/3 ~1. 5 GeV Anti-strange antiquark sc +1/3 1 0 +1/3 ~100 MeV Generation 3 Tau τ -1 2 -1/2 -1/2 1 1. "