diff --git a/Toolkit.Avalonia/ContentControlHandler.cs b/Toolkit.Avalonia/ContentControlHandler.cs
index b14046f..6a2aa0c 100644
--- a/Toolkit.Avalonia/ContentControlHandler.cs
+++ b/Toolkit.Avalonia/ContentControlHandler.cs
@@ -21,7 +21,7 @@ public class ContentControlHandler :
                     {
                         if (content is IActivated activated)
                         {
-                            await activated.OnActivated();
+                            await activated.Activated();
                         }
                     }
 
@@ -35,7 +35,7 @@ public class ContentControlHandler :
                     {
                         if (content is IDeactivated deactivated)
                         {
-                            await deactivated.OnDeactivated();
+                            await deactivated.Deactivated();
                         }
 
                         if (content is IDisposable disposable)
diff --git a/Toolkit.Avalonia/ContentDialogHandler.cs b/Toolkit.Avalonia/ContentDialogHandler.cs
index 8eafbb2..1c34ade 100644
--- a/Toolkit.Avalonia/ContentDialogHandler.cs
+++ b/Toolkit.Avalonia/ContentDialogHandler.cs
@@ -81,7 +81,7 @@ public class ContentDialogHandler(IDispatcher dispatcher) :
                         {
                             if (content is IDeactivating deactivating)
                             {
-                                await deactivating.OnDeactivating();
+                                await deactivating.Deactivating();
                             }
                        }
                     }
@@ -96,7 +96,7 @@ public class ContentDialogHandler(IDispatcher dispatcher) :
                 {
                     if (content is IActivated activated)
                     {
-                        await activated.OnActivated();
+                        await activated.Activated();
                     }
                 }
             }
@@ -109,7 +109,7 @@ public class ContentDialogHandler(IDispatcher dispatcher) :
                 {
                     if (content is IDeactivated deactivated)
                     {
-                        await deactivated.OnDeactivated();
+                        await deactivated.Deactivated();
                     }
                 }
             }
diff --git a/Toolkit.Avalonia/ContentTemplate.cs b/Toolkit.Avalonia/ContentTemplate.cs
index b7f3c4a..5c520c1 100644
--- a/Toolkit.Avalonia/ContentTemplate.cs
+++ b/Toolkit.Avalonia/ContentTemplate.cs
@@ -29,7 +29,7 @@ public class ContentTemplate :
                             {
                                 if (content is IActivated activated)
                                 {
-                                    await activated.OnActivated();
+                                    await activated.Activated();
                                 }
                             }
                         }
@@ -41,7 +41,7 @@ public class ContentTemplate :
                             {
                                 if (content is IDeactivated deactivated)
                                 {
-                                    await deactivated.OnDeactivated();
+                                    await deactivated.Deactivated();
                                 }
                             }
                         }
diff --git a/Toolkit.Avalonia/FrameHandler.cs b/Toolkit.Avalonia/FrameHandler.cs
index 33497cb..6d9a83a 100644
--- a/Toolkit.Avalonia/FrameHandler.cs
+++ b/Toolkit.Avalonia/FrameHandler.cs
@@ -37,7 +37,7 @@ public class FrameHandler :
                                 {
                                     if (content is IDeactivated deactivated)
                                     {
-                                        await deactivated.OnDeactivated();
+                                        await deactivated.Deactivated();
                                     }
 
                                     if (content is not IKeepAlive)
@@ -63,7 +63,7 @@ public class FrameHandler :
                                 {
                                     if (content is IDeactivating deactivating)
                                     {
-                                        await deactivating.OnDeactivating();
+                                        await deactivating.Deactivating();
                                     }
                                 }
                             }
@@ -74,7 +74,7 @@ public class FrameHandler :
                         {
                             if (content is IActivated activated)
                             {
-                                await activated.OnActivated();
+                                await activated.Activated();
                             }
                         }
 
@@ -89,7 +89,7 @@ public class FrameHandler :
                             {
                                 if (content is IDeactivated deactivated)
                                 {
-                                    await deactivated.OnDeactivated();
+                                    await deactivated.Deactivated();
                                 }
 
                                 if (content is IDisposable disposable)
diff --git a/Toolkit.Foundation/AppService.cs b/Toolkit.Foundation/AppService.cs
index 72a551b..dd3f5e4 100644
--- a/Toolkit.Foundation/AppService.cs
+++ b/Toolkit.Foundation/AppService.cs
@@ -10,7 +10,7 @@ public class AppService(IEnumerable<IInitialization> initializers,
     {
         foreach (IInitialization initializer in initializers)
         {
-            await initializer.OnInitialize();
+            await initializer.Initialize();
         }
 
         publisher.Publish<StartedEventArgs>();
diff --git a/Toolkit.Foundation/ComponentConfigurationViewModel.cs b/Toolkit.Foundation/ComponentConfigurationViewModel.cs
index 45ac4f9..856456f 100644
--- a/Toolkit.Foundation/ComponentConfigurationViewModel.cs
+++ b/Toolkit.Foundation/ComponentConfigurationViewModel.cs
@@ -51,10 +51,10 @@ public partial class ComponentConfigurationViewModel<TConfiguration, TValue, TAc
     [ObservableProperty]
     private object description = description;
 
-    public override Task OnActivated()
+    public override Task Activated()
     {
         Value = valueDelegate.Invoke(configuration);
-        return base.OnActivated();
+        return base.Activated();
     }
 
     public Task Handle(ChangedEventArgs<TConfiguration> args)
@@ -93,10 +93,10 @@ public partial class ComponentConfigurationViewModel<TConfiguration, TValue, TDe
     [ObservableProperty]
     private TDescription description = description;
 
-    public override Task OnActivated()
+    public override Task Activated()
     {
         Value = valueDelegate.Invoke(configuration);
-        return base.OnActivated();
+        return base.Activated();
     }
 
     public Task Handle(ChangedEventArgs<TConfiguration> args)
diff --git a/Toolkit.Foundation/ComponentHost.cs b/Toolkit.Foundation/ComponentHost.cs
index 609fc68..e6cfb31 100644
--- a/Toolkit.Foundation/ComponentHost.cs
+++ b/Toolkit.Foundation/ComponentHost.cs
@@ -23,7 +23,7 @@ public class ComponentHost(IServiceProvider services,
     {
         foreach (IInitialization initializer in initializers)
         {
-            await initializer.OnInitialize();
+            await initializer.Initialize();
         }
 
         foreach (IHostedService service in hostedServices)
diff --git a/Toolkit.Foundation/ComponentInitializer.cs b/Toolkit.Foundation/ComponentInitializer.cs
index 37f6f2f..f5c183e 100644
--- a/Toolkit.Foundation/ComponentInitializer.cs
+++ b/Toolkit.Foundation/ComponentInitializer.cs
@@ -9,7 +9,7 @@ public class ComponentInitializer(IEnumerable<IComponent> components,
     IServiceProvider provider) :
     IInitialization
 {
-    public async Task OnInitialize()
+    public async Task Initialize()
     {
         foreach (IComponent component in components)
         {
diff --git a/Toolkit.Foundation/ConfigurationInitializer.cs b/Toolkit.Foundation/ConfigurationInitializer.cs
index a75cdc9..c17b03c 100644
--- a/Toolkit.Foundation/ConfigurationInitializer.cs
+++ b/Toolkit.Foundation/ConfigurationInitializer.cs
@@ -9,7 +9,7 @@ public class ConfigurationInitializer<TConfiguration>(IConfigurationReader<TConf
     where TConfiguration :
     class
 {
-    public Task OnInitialize()
+    public Task Initialize()
     {
         if (!reader.TryRead(out TConfiguration? configuration))
         {
diff --git a/Toolkit.Foundation/ContentFactory.cs b/Toolkit.Foundation/ContentFactory.cs
index e6898c2..80ec0f9 100644
--- a/Toolkit.Foundation/ContentFactory.cs
+++ b/Toolkit.Foundation/ContentFactory.cs
@@ -20,14 +20,14 @@ public class ContentFactory(IMediator mediator,
                 {
                     if (args is IInitialization initialization)
                     {
-                        initialization.OnInitialize();
+                        initialization.Initialize();
                     }
                 }, parameters)
                 : provider.GetRequiredKeyedService(descriptor.ContentType, args =>
                 {
                     if (args is IInitialization initialization)
                     {
-                        initialization.OnInitialize();
+                        initialization.Initialize();
                     }
                 }, descriptor.Key);
 
diff --git a/Toolkit.Foundation/IActivated.cs b/Toolkit.Foundation/IActivated.cs
index d335a1e..33d75d5 100644
--- a/Toolkit.Foundation/IActivated.cs
+++ b/Toolkit.Foundation/IActivated.cs
@@ -2,5 +2,5 @@
 
 public interface IActivated
 {
-    Task OnActivated();
+    Task Activated();
 }
\ No newline at end of file
diff --git a/Toolkit.Foundation/IConfigurationInitializer.cs b/Toolkit.Foundation/IConfigurationInitializer.cs
index b8873af..a573f89 100644
--- a/Toolkit.Foundation/IConfigurationInitializer.cs
+++ b/Toolkit.Foundation/IConfigurationInitializer.cs
@@ -4,5 +4,5 @@ public interface IConfigurationInitializer<TConfiguration>
     where TConfiguration :
     class
 {
-    Task OnInitialize();
+    Task Initialize();
 }
\ No newline at end of file
diff --git a/Toolkit.Foundation/IDeactivated.cs b/Toolkit.Foundation/IDeactivated.cs
index 84bbeb4..f640164 100644
--- a/Toolkit.Foundation/IDeactivated.cs
+++ b/Toolkit.Foundation/IDeactivated.cs
@@ -2,5 +2,5 @@
 
 public interface IDeactivated
 {
-    Task OnDeactivated();
+    Task Deactivated();
 }
\ No newline at end of file
diff --git a/Toolkit.Foundation/IDeactivating.cs b/Toolkit.Foundation/IDeactivating.cs
index 4b58970..6a70c8a 100644
--- a/Toolkit.Foundation/IDeactivating.cs
+++ b/Toolkit.Foundation/IDeactivating.cs
@@ -2,5 +2,5 @@
 
 public interface IDeactivating
 {
-    Task OnDeactivating();
+    Task Deactivating();
 }
\ No newline at end of file
diff --git a/Toolkit.Foundation/IInitialization.cs b/Toolkit.Foundation/IInitialization.cs
index 71c8733..a5dc5f6 100644
--- a/Toolkit.Foundation/IInitialization.cs
+++ b/Toolkit.Foundation/IInitialization.cs
@@ -2,5 +2,5 @@
 
 public interface IInitialization
 {
-    Task OnInitialize();
+    Task Initialize();
 }
\ No newline at end of file
diff --git a/Toolkit.Foundation/ISelectable.cs b/Toolkit.Foundation/ISelectable.cs
index 3951dfd..7c484ed 100644
--- a/Toolkit.Foundation/ISelectable.cs
+++ b/Toolkit.Foundation/ISelectable.cs
@@ -2,5 +2,5 @@
 
 public interface ISelectable
 {
-    bool Selected { get; set; }
+    bool IsSelected { get; set; }
 }
\ No newline at end of file
diff --git a/Toolkit.Foundation/IValidation.cs b/Toolkit.Foundation/IValidation.cs
index 891f08f..a4d318c 100644
--- a/Toolkit.Foundation/IValidation.cs
+++ b/Toolkit.Foundation/IValidation.cs
@@ -6,7 +6,7 @@ namespace Toolkit.Foundation;
 public interface IValidation : 
     INotifyPropertyChanged
 {
-    ValidationErrorCollection Errors { get; }
+    IReadOnlyDictionary<string, string> Errors { get; }
 
     bool HasErrors { get; }
 
diff --git a/Toolkit.Foundation/Observable.cs b/Toolkit.Foundation/Observable.cs
index 38e0c11..6bd75c6 100644
--- a/Toolkit.Foundation/Observable.cs
+++ b/Toolkit.Foundation/Observable.cs
@@ -56,7 +56,7 @@ public partial class Observable(IServiceProvider provider,
         Disposer.Dispose(this);
     }
 
-    public virtual Task OnInitialize()
+    public virtual Task Initialize()
     {
         if (IsInitialized)
         {
@@ -72,20 +72,20 @@ public partial class Observable(IServiceProvider provider,
     [ObservableProperty]
     private bool isActivated;
 
-    public virtual Task OnActivated()
+    public virtual Task Activated()
     {
         IsActivated = true;
         return Task.CompletedTask;
     }
 
 
-    public virtual Task OnDeactivated()
+    public virtual Task Deactivated()
     {
         IsActivated = false;
         return Task.CompletedTask;
     }
 
-    public virtual Task OnDeactivating() =>
+    public virtual Task Deactivating() =>
         Task.CompletedTask;
 
     public void Revert()
diff --git a/Toolkit.Foundation/ObservableCollection.cs b/Toolkit.Foundation/ObservableCollection.cs
index 28a7499..f7e027c 100644
--- a/Toolkit.Foundation/ObservableCollection.cs
+++ b/Toolkit.Foundation/ObservableCollection.cs
@@ -37,6 +37,7 @@ public partial class ObservableCollection<TItem> :
     private readonly System.Collections.ObjectModel.ObservableCollection<TItem> collection = [];
 
     private readonly IDispatcher dispatcher;
+
     private readonly Queue<object> pendingEvents = [];
 
     private readonly Dictionary<string, object> trackedProperties = [];
@@ -151,7 +152,7 @@ public partial class ObservableCollection<TItem> :
         {
             if (args is IInitialization initialization)
             {
-                initialization.OnInitialize();
+                initialization.Initialize();
             }
         }, parameters);
 
@@ -403,7 +404,7 @@ public partial class ObservableCollection<TItem> :
         {
             if (args is IInitialization initialization)
             {
-                initialization.OnInitialize();
+                initialization.Initialize();
             }
         }, parameters);
 
@@ -442,7 +443,7 @@ public partial class ObservableCollection<TItem> :
         bool moveSelection = false;
         if (item is ISelectable oldSelection)
         {
-            if (oldSelection.Selected)
+            if (oldSelection.IsSelected)
             {
                 moveSelection = true;
                 SelectedItem = default;
@@ -456,7 +457,7 @@ public partial class ObservableCollection<TItem> :
         {
             if (item is ISelectable newSelection)
             {
-                newSelection.Selected = true;
+                newSelection.IsSelected = true;
                 dispatcher.Invoke(() => SelectedItem = item);
             }
         }
@@ -478,7 +479,7 @@ public partial class ObservableCollection<TItem> :
         return true;
     }
 
-    public virtual Task OnActivated()
+    public virtual Task Activated()
     {
         IsActivated = true;
         while (pendingEvents.Count > 0)
@@ -490,16 +491,16 @@ public partial class ObservableCollection<TItem> :
         return Task.CompletedTask;
     }
 
-    public virtual Task OnDeactivated()
+    public virtual Task Deactivated()
     {
         IsActivated = false;
         return Task.CompletedTask;
     }
 
-    public virtual Task OnDeactivating() =>
+    public virtual Task Deactivating() =>
         Task.CompletedTask;
 
-    public virtual Task OnInitialize()
+    public virtual Task Initialize()
     {
         if (IsInitialized)
         {
@@ -634,12 +635,12 @@ public partial class ObservableCollection<TItem> :
     {
         if (oldValue is ISelectable oldSelection)
         {
-            oldSelection.Selected = false;
+            oldSelection.IsSelected = false;
         }
 
         if (newValue is ISelectable newSelection)
         {
-            newSelection.Selected = true;
+            newSelection.IsSelected = true;
         }
     }
 
@@ -647,11 +648,11 @@ public partial class ObservableCollection<TItem> :
     {
         if (item is ISelectable newSelection)
         {
-            if (newSelection.Selected)
+            if (newSelection.IsSelected)
             {
                 if (SelectedItem is ISelectable oldSelection)
                 {
-                    oldSelection.Selected = false;
+                    oldSelection.IsSelected = false;
                 }
 
                 dispatcher.Invoke(() => SelectedItem = item);
diff --git a/Toolkit.Foundation/Validation.cs b/Toolkit.Foundation/Validation.cs
index 82e9a8c..b76561f 100644
--- a/Toolkit.Foundation/Validation.cs
+++ b/Toolkit.Foundation/Validation.cs
@@ -8,7 +8,10 @@ public class Validation(IValidatorCollection validators) :
 {
     public event PropertyChangedEventHandler? PropertyChanged;
 
-    public ValidationErrorCollection Errors { get; } = [];
+    private readonly ValidationErrorCollection errors = [];
+
+    public IReadOnlyDictionary<string, string> Errors => 
+        errors.AsReadOnly();
 
     public bool HasErrors => 
         Errors.Count > 0;
@@ -38,7 +41,7 @@ public class Validation(IValidatorCollection validators) :
     {
         if (Errors.ContainsKey(name))
         {
-            Errors.Remove(name);
+            errors.Remove(name);
         }
 
         if (Validators.TryGet(name, out Validator? validator))
@@ -47,7 +50,7 @@ public class Validation(IValidatorCollection validators) :
             {
                 if (!validator.TryValidate(out string? message))
                 {
-                    Errors[name] = message ?? "";
+                    errors[name] = message ?? "";
                 }
             }
         }
@@ -60,14 +63,14 @@ public class Validation(IValidatorCollection validators) :
 
     public bool Validate()
     {
-        Errors.Clear();
+        errors.Clear();
         foreach (Validator? validator in Validators)
         {
             if (validator.PropertyName is string name)
             {
                 if (!validator.TryValidate(out string? message))
                 {
-                    Errors[name] = message ?? "";
+                    errors[name] = message ?? "";
                 }
             }
         }
diff --git a/Toolkit.Foundation/ValidationErrorCollection.cs b/Toolkit.Foundation/ValidationErrorCollection.cs
index 1c360db..e551093 100644
--- a/Toolkit.Foundation/ValidationErrorCollection.cs
+++ b/Toolkit.Foundation/ValidationErrorCollection.cs
@@ -42,7 +42,7 @@ public class ValidationErrorCollection :
 
     public string this[string key]
     {
-        get => items.ContainsKey(key) ? items[key] : "";
+        get => items.TryGetValue(key, out string? value) ? value : "";
         set
         {
             bool replace = items.TryGetValue(key, out var old);
diff --git a/Toolkit.UI.Avalonia/InvokeNavigationViewItemAction.cs b/Toolkit.UI.Avalonia/InvokeNavigationViewItemAction.cs
index 393791c..7f86405 100644
--- a/Toolkit.UI.Avalonia/InvokeNavigationViewItemAction.cs
+++ b/Toolkit.UI.Avalonia/InvokeNavigationViewItemAction.cs
@@ -21,7 +21,7 @@ public class InvokeNavigationViewItemAction :
                 {
                     if (collection is { Count: > 0 } && collection[0] is ISelectable selectable)
                     {
-                        selectable.Selected = true;
+                        selectable.IsSelected = true;
                     }
                 }
             }, DispatcherPriority.ContextIdle);
@@ -35,7 +35,7 @@ public class InvokeNavigationViewItemAction :
                 {
                     if (collection is { Count: > 0 } && collection[0] is ISelectable selectable)
                     {
-                        selectable.Selected = true;
+                        selectable.IsSelected = true;
                     }
                 }
             }, DispatcherPriority.ContextIdle);