n-layer

So, I've looked at some posts about the Specification Pattern here, and haven't found an answer to this one yet. My question is, in an n-layered architecture, where exactly should me Specifications get "newed" up? I could put them in my Service Layer (aka, Application layer it's sometimes called... basically, something an .aspx code-behind would talk to), but I feel like by doing that, I'm letting business rules leak out of the Domain. If the Domain objects are accessed some other way (besides the Service Layer), the Domain objects cannot enforce their own business rules. I could inject the

I am going to develop a winform project of considerable size. I am planning to use Entity Framework as ORM tool. Now I am searching for an architecture(MVC/MVP/MVVM etc..) to implement all these. Firstly there are few choices for n-layered architecture for windows forms and most those I get are written prior to EF came into market. I got a framework called Rocket Framework from codeplex( http://rocketframework.codeplex.com ) I have looked around it but am skeptical that it will accommodate a wide range of requirements. If anyone has already discovered the wheel already, please guide me through

After spending a couple months studying DDD methodology, I've now began to apply these concepts into actual products at my company. In fact, I've been tasked with creating a suitable and maintainable architecture for future development. We have decided to make use of the following technologies: EF4 (really v2), Unity The amount of information I've obtained has been most enlightening, however, I'm left with several questions in best practice: Question #1: DTOs - Best Practices I have my domain objects (POCO classes). There are several ways to implement these classes. Traditional Approach:

So my asp.net is very very rusty, and i'm trying to get back into best practices and what not. So, I whip out google and start looking for examples and samples and tutorials, but what do I find? Old crusty stuff that tends to be written even before "the latest" technology was released back in the stone age. Sure, the concepts may still hold up. But the actual implementations are basically useless. I'm looking for something using Linq, n-layers (not tiers. Tiers can be a layer, but a layer is not necessarily a tier) some kind of current ORM (L2S, EF, etc..) and some real-world stuff, not

I am contemplating about using an MVC pattern in my new project and I can clearly see the main advantage of being able to put the data layer (the model) a little closer to the presentation layer (the view), which will allow a little increase in application speed. But apart from performance stand point are there any other advantages of MVC over the view-logic-data layered type pattern? EDIT: For those who's interested I just uploaded a sample PHP code that I created to test the use of MVC. I purposly omitted all the security checks to make the code a little easier to read. Please don't