diff --git a/Advanced NSOperations.xcodeproj/project.pbxproj b/Advanced NSOperations.xcodeproj/project.pbxproj
index 90e4962..b35d0dc 100644
--- a/Advanced NSOperations.xcodeproj/project.pbxproj	
+++ b/Advanced NSOperations.xcodeproj/project.pbxproj	
@@ -19,13 +19,13 @@
 		553F50161B08E98A005F991E /* LoadModelOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50151B08E98A005F991E /* LoadModelOperation.swift */; };
 		55817C3A1B18FDF8001C0CE2 /* EarthquakeOperationQueue.swift in Sources */ = {isa = PBXBuildFile; fileRef = 551B9C061AEB2D7800302388 /* EarthquakeOperationQueue.swift */; };
 		55817C3B1B18FDF8001C0CE2 /* ExclusivityController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55CD4D201AF5C05300E3A9E3 /* ExclusivityController.swift */; };
-		55817C3D1B18FDF8001C0CE2 /* EarthquakeBlockOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55857B3A1AF20DE800219D5A /* EarthquakeBlockOperation.swift */; };
 		55817C3C1B18FDF8001C0CE2 /* EarthquakeOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 551B9C021AEB1CA900302388 /* EarthquakeOperation.swift */; };
+		55817C3D1B18FDF8001C0CE2 /* EarthquakeBlockOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55857B3A1AF20DE800219D5A /* EarthquakeBlockOperation.swift */; };
 		55817C3E1B18FDF8001C0CE2 /* GroupOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55727FB11AF2798C00EC6916 /* GroupOperation.swift */; };
 		55817C3F1B18FDF8001C0CE2 /* URLSessionTaskOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55727FB91AF2849E00EC6916 /* URLSessionTaskOperation.swift */; };
 		55817C401B18FDF8001C0CE2 /* LocationOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50031B07FB5E005F991E /* LocationOperation.swift */; };
 		55817C411B18FDF8001C0CE2 /* DelayOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50131B0832D2005F991E /* DelayOperation.swift */; };
-		55817C421B18FDF8001C0CE2 /* OperationObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50051B081760005F991E /* OperationObserver.swift */; };
+		55817C421B18FDF8001C0CE2 /* EarthquakeOperationObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50051B081760005F991E /* EarthquakeOperationObserver.swift */; };
 		55817C431B18FDF8001C0CE2 /* BlockObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F50081B0817D2005F991E /* BlockObserver.swift */; };
 		55817C441B18FDF8001C0CE2 /* TimeoutObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 55AD643C1B128CC3000EF5CB /* TimeoutObserver.swift */; };
 		55817C451B18FDF8001C0CE2 /* OperationErrors.swift in Sources */ = {isa = PBXBuildFile; fileRef = 553F2D651B00041100BF4093 /* OperationErrors.swift */; };
@@ -96,7 +96,7 @@
 		553C5AC61AF6D2EB002FC47A /* HealthCondition.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = HealthCondition.swift; sourceTree = "<group>"; };
 		553F2D651B00041100BF4093 /* OperationErrors.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OperationErrors.swift; sourceTree = "<group>"; };
 		553F50031B07FB5E005F991E /* LocationOperation.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = LocationOperation.swift; sourceTree = "<group>"; };
-		553F50051B081760005F991E /* OperationObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OperationObserver.swift; sourceTree = "<group>"; };
+		553F50051B081760005F991E /* EarthquakeOperationObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = EarthquakeOperationObserver.swift; sourceTree = "<group>"; };
 		553F50081B0817D2005F991E /* BlockObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = BlockObserver.swift; sourceTree = "<group>"; };
 		553F500E1B081A9D005F991E /* NetworkObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = NetworkObserver.swift; sourceTree = "<group>"; };
 		553F50101B082BCF005F991E /* BackgroundObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = BackgroundObserver.swift; sourceTree = "<group>"; };
@@ -227,7 +227,7 @@
 		553F50071B0817BB005F991E /* Observers */ = {
 			isa = PBXGroup;
 			children = (
-				553F50051B081760005F991E /* OperationObserver.swift */,
+				553F50051B081760005F991E /* EarthquakeOperationObserver.swift */,
 				553F50081B0817D2005F991E /* BlockObserver.swift */,
 				55AD643C1B128CC3000EF5CB /* TimeoutObserver.swift */,
 			);
@@ -417,7 +417,7 @@
 				55817C3E1B18FDF8001C0CE2 /* GroupOperation.swift in Sources */,
 				55817C491B18FDF8001C0CE2 /* NoCancelledDependencies.swift in Sources */,
 				55817C581B18FDF8001C0CE2 /* UIUserNotifications+Operations.swift in Sources */,
-				55817C421B18FDF8001C0CE2 /* OperationObserver.swift in Sources */,
+				55817C421B18FDF8001C0CE2 /* EarthquakeOperationObserver.swift in Sources */,
 				5521B4821B700C87007089CE /* NSLock+Operations.swift in Sources */,
 				553F500F1B081A9D005F991E /* NetworkObserver.swift in Sources */,
 				55817C551B18FDF8001C0CE2 /* Dictionary+Operations.swift in Sources */,
diff --git a/Earthquakes/BackgroundObserver.swift b/Earthquakes/BackgroundObserver.swift
index 5b3b7b1..d1b2f1e 100644
--- a/Earthquakes/BackgroundObserver.swift
+++ b/Earthquakes/BackgroundObserver.swift
@@ -9,13 +9,13 @@ Contains the code related to automatic background tasks
 import UIKit
 
 /**
-    `BackgroundObserver` is an `OperationObserver` that will automatically begin
-    and end a background task if the application transitions to the background.
-    This would be useful if you had a vital `Operation` whose execution *must* complete,
-    regardless of the activation state of the app. Some kinds network connections
-    may fall in to this category, for example.
+    `BackgroundObserver` is an `EarthquakeOperationObserver` that will
+    automatically begin and end a background task if the application transitions to the
+    background. This would be useful if you had a vital `EarthquakeOperation`
+    whose execution *must* complete, regardless of the activation state of the app.
+    Some kinds network connections may fall in to this category, for example.
 */
-class BackgroundObserver: NSObject, OperationObserver {
+class BackgroundObserver: NSObject, EarthquakeOperationObserver {
     // MARK: Properties
 
     private var identifier = UIBackgroundTaskIdentifier.invalid
diff --git a/Earthquakes/EarthquakeTableViewController.swift b/Earthquakes/EarthquakeTableViewController.swift
index 037b5b9..87842e6 100644
--- a/Earthquakes/EarthquakeTableViewController.swift
+++ b/Earthquakes/EarthquakeTableViewController.swift
@@ -89,7 +89,7 @@ class EarthquakeTableViewController: UITableViewController {
 
         /*
             We could present the share sheet manually, but by putting it inside
-            an `Operation`, we can make it mutually exclusive with other operations
+            an `EarthquakeOperation`, we can make it mutually exclusive with other operations
             that modify the view controller hierarchy.
         */
         let shareOperation = EarthquakeBlockOperation { (continuation: @escaping () -> Void) in
diff --git a/Earthquakes/GetEarthquakesOperation.swift b/Earthquakes/GetEarthquakesOperation.swift
index eda5a03..50ad380 100644
--- a/Earthquakes/GetEarthquakesOperation.swift
+++ b/Earthquakes/GetEarthquakesOperation.swift
@@ -8,7 +8,7 @@ This file sets up the operations to download and parse earthquake data. It will
 
 import CoreData
 
-/// A composite `Operation` to both download and parse earthquake data.
+/// A composite `EarthquakeOperation` to both download and parse earthquake data.
 class GetEarthquakesOperation: GroupOperation {
     // MARK: Properties
     
diff --git a/Earthquakes/LoadModelOperation.swift b/Earthquakes/LoadModelOperation.swift
index 122be85..babeadb 100644
--- a/Earthquakes/LoadModelOperation.swift
+++ b/Earthquakes/LoadModelOperation.swift
@@ -9,7 +9,7 @@ This file contains the code to create the Core Data stack.
 import CoreData
 
 /**
-    An `Operation` subclass that loads the Core Data stack. If this operation fails,
+    An `EarthquakeOperation` subclass that loads the Core Data stack. If this operation fails,
     it will produce an `AlertOperation` that will offer to retry the operation.
 */
 class LoadModelOperation: EarthquakeOperation {
diff --git a/Earthquakes/MoreInformationOperation.swift b/Earthquakes/MoreInformationOperation.swift
index 0723ae9..4672251 100644
--- a/Earthquakes/MoreInformationOperation.swift
+++ b/Earthquakes/MoreInformationOperation.swift
@@ -9,7 +9,7 @@ This file contains the code to present more information about an earthquake as a
 import Foundation
 import SafariServices
 
-/// An `Operation` to display an `URL` in an app-modal `SFSafariViewController`.
+/// An `EarthquakeOperation` to display an `URL` in an app-modal `SFSafariViewController`.
 class MoreInformationOperation: EarthquakeOperation {
     // MARK: Properties
 
diff --git a/Earthquakes/NetworkObserver.swift b/Earthquakes/NetworkObserver.swift
index 0480a07..6fde451 100644
--- a/Earthquakes/NetworkObserver.swift
+++ b/Earthquakes/NetworkObserver.swift
@@ -9,10 +9,11 @@ Contains the code to manage the visibility of the network activity indicator
 import UIKit
 
 /**
-    An `OperationObserver` that will cause the network activity indicator to appear
-    as long as the `Operation` to which it is attached is executing.
+    An `EarthquakeOperationObserver` that will cause the network activity
+    indicator to appear as long as the `EarthquakeOperation` to which it is
+    attached is executing.
 */
-struct NetworkObserver: OperationObserver {
+struct NetworkObserver: EarthquakeOperationObserver {
     // MARK: Initilization
 
     init() { }
diff --git a/Earthquakes/Operations/BlockObserver.swift b/Earthquakes/Operations/BlockObserver.swift
index fbd9cf5..28a19fa 100644
--- a/Earthquakes/Operations/BlockObserver.swift
+++ b/Earthquakes/Operations/BlockObserver.swift
@@ -10,9 +10,9 @@ import Foundation
 
 /**
     The `BlockObserver` is a way to attach arbitrary blocks to significant events
-    in an `Operation`'s lifecycle.
+    in an `EarthquakeOperation`'s lifecycle.
 */
-struct BlockObserver: OperationObserver {
+struct BlockObserver: EarthquakeOperationObserver {
     // MARK: Properties
     
     private let startHandler: ((EarthquakeOperation) -> Void)?
diff --git a/Earthquakes/Operations/CalendarCondition.swift b/Earthquakes/Operations/CalendarCondition.swift
index 5dbaf98..11fe0af 100644
--- a/Earthquakes/Operations/CalendarCondition.swift
+++ b/Earthquakes/Operations/CalendarCondition.swift
@@ -50,7 +50,7 @@ struct CalendarCondition: OperationCondition {
 private let SharedEventStore = EKEventStore()
 
 /**
-    A private `Operation` that will request access to the user's Calendar/Reminders,
+    A private `EarthquakeOperation` that will request access to the user's Calendar/Reminders,
     if it has not already been granted.
 */
 private class CalendarPermissionOperation: EarthquakeOperation {
diff --git a/Earthquakes/Operations/DelayOperation.swift b/Earthquakes/Operations/DelayOperation.swift
index 1be41e6..202d626 100644
--- a/Earthquakes/Operations/DelayOperation.swift
+++ b/Earthquakes/Operations/DelayOperation.swift
@@ -9,15 +9,15 @@ This file shows how to make an operation that efficiently waits.
 import Foundation
 
 /**
-    `DelayOperation` is an `Operation` that will simply wait for a given time
-    interval, or until a specific `NSDate`.
+    `DelayOperation` is an `EarthquakeOperation` that will simply wait for a
+    given time interval, or until a specific `Date`.
 
     It is important to note that this operation does **not** use the `sleep()`
     function, since that is inefficient and blocks the thread on which it is called.
-    Instead, this operation uses `dispatch_after` to know when the appropriate amount
-    of time has passed.
+    Instead, this operation uses `DispatchQueue.asyncAfter` to know
+    when the appropriate amount of time has passed.
 
-    If the interval is negative, or the `NSDate` is in the past, then this operation
+    If the interval is negative, or the `Date` is in the past, then this operation
     immediately finishes.
 */
 class DelayOperation: EarthquakeOperation {
diff --git a/Earthquakes/Operations/EarthquakeBlockOperation.swift b/Earthquakes/Operations/EarthquakeBlockOperation.swift
index b98ca77..dc59f6d 100644
--- a/Earthquakes/Operations/EarthquakeBlockOperation.swift
+++ b/Earthquakes/Operations/EarthquakeBlockOperation.swift
@@ -3,7 +3,7 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-This code shows how to create a simple subclass of Operation.
+This code shows how to create a simple subclass of EarthquakeOperation.
 */
 
 import Foundation
diff --git a/Earthquakes/Operations/EarthquakeOperation.swift b/Earthquakes/Operations/EarthquakeOperation.swift
index 7a339d3..1b5cd3e 100644
--- a/Earthquakes/Operations/EarthquakeOperation.swift
+++ b/Earthquakes/Operations/EarthquakeOperation.swift
@@ -3,13 +3,13 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-This file contains the foundational subclass of NSOperation.
+This file contains the foundational subclass of Operation.
 */
 
 import Foundation
 
 /**
-    The subclass of `NSOperation` from which all other operations should be derived.
+    The subclass of `Operation` from which all other operations should be derived.
     This class adds both Conditions and Observers, which allow the operation to define
     extended readiness requirements, as well as notify many interested parties
     about interesting operation state changes
@@ -29,31 +29,31 @@ class EarthquakeOperation: Operation {
     // MARK: State Management
     
     fileprivate enum State: Int, Comparable {
-        /// The initial state of an `Operation`.
+        /// The initial state of an `EarthquakeOperation`.
         case Initialized
         
-        /// The `Operation` is ready to begin evaluating conditions.
+        /// The `EarthquakeOperation` is ready to begin evaluating conditions.
         case Pending
         
-        /// The `Operation` is evaluating conditions.
+        /// The `EarthquakeOperation` is evaluating conditions.
         case EvaluatingConditions
         
         /**
-            The `Operation`'s conditions have all been satisfied, and it is ready
+            The `EarthquakeOperation`'s conditions have all been satisfied, and it is ready
             to execute.
         */
         case Ready
         
-        /// The `Operation` is executing.
+        /// The `EarthquakeOperation` is executing.
         case Executing
         
         /**
-            Execution of the `Operation` has finished, but it has not yet notified
+            Execution of the `EarthquakeOperation` has finished, but it has not yet notified
             the queue of this.
         */
         case Finishing
         
-        /// The `Operation` has finished executing.
+        /// The `EarthquakeOperation` has finished executing.
         case Finished
         
         func canTransitionToState(target: State) -> Bool {
@@ -79,7 +79,7 @@ class EarthquakeOperation: Operation {
     }
     
     /**
-        Indicates that the Operation can now begin to evaluate readiness conditions,
+        Indicates that the EarthquakeOperation can now begin to evaluate readiness conditions,
         if appropriate.
     */
     func willEnqueue() {
@@ -194,9 +194,9 @@ class EarthquakeOperation: Operation {
         conditions.append(condition)
     }
     
-    private(set) var observers = [OperationObserver]()
+    private(set) var observers = [EarthquakeOperationObserver]()
     
-    func addObserver(observer: OperationObserver) {
+    func addObserver(observer: EarthquakeOperationObserver) {
         assert(state < .Executing, "Cannot modify observers after execution has begun.")
         
         observers.append(observer)
@@ -211,7 +211,7 @@ class EarthquakeOperation: Operation {
     // MARK: Execution and Cancellation
     
     override final func start() {
-        // NSOperation.start() contains important logic that shouldn't be bypassed.
+        // Operation.start() contains important logic that shouldn't be bypassed.
         super.start()
         
         // If the operation has been cancelled, we still need to enter the "Finished" state.
@@ -238,12 +238,12 @@ class EarthquakeOperation: Operation {
     }
     
     /**
-        `execute()` is the entry point of execution for all `Operation` subclasses.
-        If you subclass `Operation` and wish to customize its execution, you would
-        do so by overriding the `execute()` method.
+        `execute()` is the entry point of execution for all `EarthquakeOperation`
+        subclasses. If you subclass `EarthquakeOperation` and wish to customize its
+        execution, you would do so by overriding the `execute()` method.
         
-        At some point, your `Operation` subclass must call one of the "finish"
-        methods defined below; this is how you indicate that your operation has
+        At some point, your `EarthquakeOperation` subclass must call one of the
+        "finish" methods defined below; this is how you indicate that your operation has
         finished its execution, and that operations dependent on yours can re-evaluate
         their readiness state.
     */
diff --git a/Earthquakes/Operations/OperationObserver.swift b/Earthquakes/Operations/EarthquakeOperationObserver.swift
similarity index 68%
rename from Earthquakes/Operations/OperationObserver.swift
rename to Earthquakes/Operations/EarthquakeOperationObserver.swift
index 86cf0dc..a70c16b 100644
--- a/Earthquakes/Operations/OperationObserver.swift
+++ b/Earthquakes/Operations/EarthquakeOperationObserver.swift
@@ -12,16 +12,16 @@ import Foundation
     The protocol that types may implement if they wish to be notified of significant
     operation lifecycle events.
 */
-protocol OperationObserver {
+protocol EarthquakeOperationObserver {
     
-    /// Invoked immediately prior to the `Operation`'s `execute()` method.
+    /// Invoked immediately prior to the `EarthquakeOperation`'s `execute()` method.
     func operationDidStart(operation: EarthquakeOperation)
     
-    /// Invoked when `Operation.produceOperation(_:)` is executed.
+    /// Invoked when `EarthquakeOperation.produceOperation(_:)` is executed.
     func operation(operation: EarthquakeOperation, didProduceOperation newOperation: Operation)
     
     /**
-        Invoked as an `Operation` finishes, along with any errors produced during
+        Invoked as an `EarthquakeOperation` finishes, along with any errors produced during
         execution (or readiness evaluation).
     */
     func operationDidFinish(operation: EarthquakeOperation, errors: [NSError])
diff --git a/Earthquakes/Operations/EarthquakeOperationQueue.swift b/Earthquakes/Operations/EarthquakeOperationQueue.swift
index 4486996..d953ab4 100644
--- a/Earthquakes/Operations/EarthquakeOperationQueue.swift
+++ b/Earthquakes/Operations/EarthquakeOperationQueue.swift
@@ -3,20 +3,20 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-This file contains an NSOperationQueue subclass.
+This file contains an OperationQueue subclass.
 */
 
 import Foundation
 
 /**
-    The delegate of an `OperationQueue` can respond to `Operation` lifecycle
-    events by implementing these methods.
+    The delegate of an `EarthquakeOperationQueue` can respond to `EarthquakeOperation`
+    lifecycle events by implementing these methods.
 
-    In general, implementing `OperationQueueDelegate` is not necessary; you would
-    want to use an `OperationObserver` instead. However, there are a couple of
-    situations where using `OperationQueueDelegate` can lead to simpler code.
+    In general, implementing `EarthquakeOperationQueueDelegate` is not necessary; you would
+    want to use an `EarthquakeOperationObserver` instead. However, there are a couple of
+    situations where using `EarthquakeOperationQueueDelegate` can lead to simpler code.
     For example, `GroupOperation` is the delegate of its own internal
-    `OperationQueue` and uses it to manage dependencies.
+    `EarthquakeOperationQueue` and uses it to manage dependencies.
 */
 @objc protocol EarthquakeOperationQueueDelegate: NSObjectProtocol {
     @objc optional func operationQueue(operationQueue: EarthquakeOperationQueue, willAddOperation operation: Operation)
@@ -24,8 +24,8 @@ import Foundation
 }
 
 /**
-    `OperationQueue` is an `NSOperationQueue` subclass that implements a large
-    number of "extra features" related to the `Operation` class:
+    `EarthquakeOperationQueue` is an `OperationQueue` subclass that implements a large
+    number of "extra features" related to the `EarthquakeOperation` class:
     
     - Notifying a delegate of all operation completion
     - Extracting generated dependencies from operation conditions
@@ -36,7 +36,7 @@ class EarthquakeOperationQueue: OperationQueue {
     
     override func addOperation(_ operation: Operation) {
         if let op = operation as? EarthquakeOperation {
-            // Set up a `BlockObserver` to invoke the `OperationQueueDelegate` method.
+            // Set up a `BlockObserver` to invoke the `EarthquakeOperationQueueDelegate` method.
             let delegate = BlockObserver(
                 startHandler: nil,
                 produceHandler: { [weak self] in
@@ -91,10 +91,10 @@ class EarthquakeOperationQueue: OperationQueue {
         }
         else {
             /*
-                For regular `NSOperation`s, we'll manually call out to the queue's
-                delegate we don't want to just capture "operation" because that
-                would lead to the operation strongly referencing itself and that's
-                the pure definition of a memory leak.
+                For regular `EarthquakeOperation`s, we'll manually call out to the
+                queue's delegate we don't want to just capture "operation" because
+                that would lead to the operation strongly referencing itself and
+                that's the pure definition of a memory leak.
             */
             operation.addCompletionBlock { [weak self, weak operation] in
                 guard let queue = self, let operation = operation else { return }
diff --git a/Earthquakes/Operations/ExclusivityController.swift b/Earthquakes/Operations/ExclusivityController.swift
index a7c7903..2012799 100644
--- a/Earthquakes/Operations/ExclusivityController.swift
+++ b/Earthquakes/Operations/ExclusivityController.swift
@@ -10,9 +10,10 @@ import Foundation
 
 /**
     `ExclusivityController` is a singleton to keep track of all the in-flight
-    `Operation` instances that have declared themselves as requiring mutual exclusivity.
-    We use a singleton because mutual exclusivity must be enforced across the entire
-    app, regardless of the `OperationQueue` on which an `Operation` was executed.
+    `EarthquakeOperation` instances that have declared themselves as requiring
+    mutual exclusivity. We use a singleton because mutual exclusivity must be enforced
+    across the entire app, regardless of the `EarthquakeOperationQueue` on which an
+    `EarthquakeOperation` was executed.
 */
 class ExclusivityController {
     static let sharedExclusivityController = ExclusivityController()
diff --git a/Earthquakes/Operations/GroupOperation.swift b/Earthquakes/Operations/GroupOperation.swift
index b845848..1d33631 100644
--- a/Earthquakes/Operations/GroupOperation.swift
+++ b/Earthquakes/Operations/GroupOperation.swift
@@ -9,7 +9,7 @@ This file shows how operations can be composed together to form new operations.
 import Foundation
 
 /**
-    A subclass of `Operation` that executes zero or more operations as part of its
+    A subclass of `EarthquakeOperation` that executes zero or more operations as part of its
     own execution. This class of operation is very useful for abstracting several
     smaller operations into a larger operation. As an example, the `GetEarthquakesOperation`
     is composed of both a `DownloadEarthquakesOperation` and a `ParseEarthquakesOperation`.
diff --git a/Earthquakes/Operations/HealthCondition.swift b/Earthquakes/Operations/HealthCondition.swift
index 9e4e26f..5a2a327 100644
--- a/Earthquakes/Operations/HealthCondition.swift
+++ b/Earthquakes/Operations/HealthCondition.swift
@@ -12,7 +12,7 @@ import HealthKit
 import UIKit
 
 /**
-    A condition to indicate an `Operation` requires access to the user's health
+    A condition to indicate an `EarthquakeOperation` requires access to the user's health
     data.
 */
 struct HealthCondition: OperationCondition {
@@ -92,7 +92,7 @@ struct HealthCondition: OperationCondition {
 }
 
 /**
-    A private `Operation` that will request access to the user's health data, if
+    A private `EarthquakeOperation` that will request access to the user's health data, if
     it has not already been granted.
 */
 private class HealthPermissionOperation: EarthquakeOperation {
diff --git a/Earthquakes/Operations/LocationCondition.swift b/Earthquakes/Operations/LocationCondition.swift
index 17870ae..a495303 100644
--- a/Earthquakes/Operations/LocationCondition.swift
+++ b/Earthquakes/Operations/LocationCondition.swift
@@ -79,7 +79,7 @@ struct LocationCondition: OperationCondition {
 }
 
 /**
-    A private `Operation` that will request permission to access the user's location,
+    A private `EarthquakeOperation` that will request permission to access the user's location,
     if permission has not already been granted.
 */
 private class LocationPermissionOperation: EarthquakeOperation {
diff --git a/Earthquakes/Operations/LocationOperation.swift b/Earthquakes/Operations/LocationOperation.swift
index 0862493..b9c6eb1 100644
--- a/Earthquakes/Operations/LocationOperation.swift
+++ b/Earthquakes/Operations/LocationOperation.swift
@@ -10,10 +10,10 @@ import Foundation
 import CoreLocation
 
 /**
-    `LocationOperation` is an `Operation` subclass to do a "one-shot" request to
-    get the user's current location, with a desired accuracy. This operation will
-    prompt for `WhenInUse` location authorization, if the app does not already
-    have it.
+    `LocationOperation` is an `EarthquakeOperation` subclass to do
+    a "one-shot" request to get the user's current location, with a desired accuracy.
+    This operation will prompt for `WhenInUse` location authorization, if the app
+    does not already have it.
 */
 class LocationOperation: EarthquakeOperation, CLLocationManagerDelegate {
     // MARK: Properties
diff --git a/Earthquakes/Operations/NSOperation+Operations.swift b/Earthquakes/Operations/NSOperation+Operations.swift
index 54f6662..a97c4be 100644
--- a/Earthquakes/Operations/NSOperation+Operations.swift
+++ b/Earthquakes/Operations/NSOperation+Operations.swift
@@ -3,14 +3,14 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-A convenient extension to Foundation.NSOperation.
+A convenient extension to Foundation.Operation.
 */
 
 import Foundation
 
 extension Operation {
     /**
-        Add a completion block to be executed after the `NSOperation` enters the
+        Add a completion block to be executed after the `Operation` enters the
         "finished" state.
     */
     func addCompletionBlock(block: @escaping () -> Void) {
diff --git a/Earthquakes/Operations/OperationCondition.swift b/Earthquakes/Operations/OperationCondition.swift
index 0cd05d8..03494fa 100644
--- a/Earthquakes/Operations/OperationCondition.swift
+++ b/Earthquakes/Operations/OperationCondition.swift
@@ -3,7 +3,7 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-This file contains the fundamental logic relating to Operation conditions.
+This file contains the fundamental logic relating to EarthquakeOperation conditions.
 */
 
 import Foundation
@@ -32,9 +32,9 @@ protocol OperationCondition {
         operation is executed first. Use this method to return an operation that
         (for example) asks for permission to perform the operation
         
-        - parameter operation: The `Operation` to which the Condition has been added.
-        - returns: An `NSOperation`, if a dependency should be automatically added. Otherwise, `nil`.
-        - note: Only a single operation may be returned as a dependency. If you
+        - Parameter operation: The `EarthquakeOperation` to which the Condition has been added.
+        - Returns: An `Operation`, if a dependency should be automatically added. Otherwise, `nil`.
+        - Note: Only a single operation may be returned as a dependency. If you
             find that you need to return multiple operations, then you should be
             expressing that as multiple conditions. Alternatively, you could return
             a single `GroupOperation` that executes multiple operations internally.
diff --git a/Earthquakes/Operations/PhotosCondition.swift b/Earthquakes/Operations/PhotosCondition.swift
index e065a04..f6f27ef 100644
--- a/Earthquakes/Operations/PhotosCondition.swift
+++ b/Earthquakes/Operations/PhotosCondition.swift
@@ -38,7 +38,7 @@ struct PhotosCondition: OperationCondition {
 }
 
 /**
-    A private `Operation` that will request access to the user's Photos, if it
+    A private `EarthquakeOperation` that will request access to the user's Photos, if it
     has not already been granted.
 */
 private class PhotosPermissionOperation: EarthquakeOperation {
diff --git a/Earthquakes/Operations/RemoteNotificationCondition.swift b/Earthquakes/Operations/RemoteNotificationCondition.swift
index 50b6349..d9073a8 100644
--- a/Earthquakes/Operations/RemoteNotificationCondition.swift
+++ b/Earthquakes/Operations/RemoteNotificationCondition.swift
@@ -68,7 +68,7 @@ struct RemoteNotificationCondition: OperationCondition {
 }
 
 /**
-    A private `Operation` to request a push notification token from the `UIApplication`.
+    A private `EarthquakeOperation` to request a push notification token from the `UIApplication`.
     
     - note: This operation is used for *both* the generated dependency **and**
         condition evaluation, since there is no "easy" way to retrieve the push
diff --git a/Earthquakes/Operations/TimeoutObserver.swift b/Earthquakes/Operations/TimeoutObserver.swift
index edadff9..93f6a7d 100644
--- a/Earthquakes/Operations/TimeoutObserver.swift
+++ b/Earthquakes/Operations/TimeoutObserver.swift
@@ -9,10 +9,10 @@ This file shows how to implement the OperationObserver protocol.
 import Foundation
 
 /**
-    `TimeoutObserver` is a way to make an `Operation` automatically time out and
+    `TimeoutObserver` is a way to make an `EarthquakeOperation` automatically time out and
     cancel after a specified time interval.
 */
-struct TimeoutObserver: OperationObserver {
+struct TimeoutObserver {
     // MARK: Properties
 
     static let timeoutKey = "Timeout"
@@ -24,9 +24,11 @@ struct TimeoutObserver: OperationObserver {
     init(timeout: Int) {
         self.timeout = timeout
     }
-    
-    // MARK: OperationObserver
-    
+}
+
+// MARK: EarthquakeOperationObserver
+
+extension TimeoutObserver: EarthquakeOperationObserver {    
     func operationDidStart(operation: EarthquakeOperation) {
         // When the operation starts, queue up a block to cause it to time out.
         DispatchQueue.global(qos: .default).asyncAfter(deadline: .now() + .seconds(timeout)) {
diff --git a/Earthquakes/Operations/URLSessionTaskOperation.swift b/Earthquakes/Operations/URLSessionTaskOperation.swift
index 550f709..348fd1b 100644
--- a/Earthquakes/Operations/URLSessionTaskOperation.swift
+++ b/Earthquakes/Operations/URLSessionTaskOperation.swift
@@ -3,7 +3,7 @@ Copyright (C) 2015 Apple Inc. All Rights Reserved.
 See LICENSE.txt for this sample’s licensing information
 
 Abstract:
-Shows how to lift operation-like objects in to the NSOperation world.
+Shows how to lift operation-like objects in to the Operation world.
 */
 
 import Foundation
@@ -11,8 +11,8 @@ import Foundation
 private var URLSessionTaksOperationKVOContext = 0
 
 /**
-    `URLSessionTaskOperation` is an `Operation` that lifts an `URLSessionTask`
-    into an operation.
+    `URLSessionTaskOperation` is an `EarthquakeOperation` that lifts
+    an `URLSessionTask` into an operation.
 
     Note that this operation does not participate in any of the delegate callbacks \
     of an `URLSession`, but instead uses Key-Value-Observing to know when the
diff --git a/Earthquakes/Operations/UserNotificationCondition.swift b/Earthquakes/Operations/UserNotificationCondition.swift
index 9f17a09..34da5d6 100644
--- a/Earthquakes/Operations/UserNotificationCondition.swift
+++ b/Earthquakes/Operations/UserNotificationCondition.swift
@@ -82,7 +82,7 @@ struct UserNotificationCondition: OperationCondition {
 }
 
 /**
-    A private `Operation` subclass to register a `UIUserNotificationSettings`
+    A private `EarthquakeOperation` subclass to register a `UIUserNotificationSettings`
     object with a `UIApplication`, prompting the user for permission if necessary.
 */
 private class UserNotificationPermissionOperation: EarthquakeOperation {
diff --git a/Earthquakes/ParseEarthquakesOperation.swift b/Earthquakes/ParseEarthquakesOperation.swift
index cb44140..caab84b 100644
--- a/Earthquakes/ParseEarthquakesOperation.swift
+++ b/Earthquakes/ParseEarthquakesOperation.swift
@@ -58,7 +58,7 @@ private struct ParsedEarthquake {
     }
 }
 
-/// An `Operation` to parse earthquakes out of a downloaded feed from the USGS.
+/// An `EarthquakeOperation` to parse earthquakes out of a downloaded feed from the USGS.
 class ParseEarthquakesOperation: EarthquakeOperation {
     let cacheFile: URL
     let context: NSManagedObjectContext