Hi, I found "testNilWhenErrorInLookup" indeed, sorry for that. "testRaisesErrorSendWhenErrorInLookup" is still missing though. Maybe the name has changed to this one: testMethodNotFoundRaiseError "(self  run: #testMethodNotFoundRaiseError)" self should: [aPoint unarySend: #zork] raise: Error. About the lookup method, I should not use "lookup: selector from: anObjObject" at all right? - Edouard On Thursday, November 19, 2015 8:24 PM, stepharo <stepharo@free.fr> wrote: I checked testNilWhenErrorInLookup    "(self selector: #testNilWhenErrorInLookup) run"       self assert: (pointClass lookup: #zork) isNil.    "The method zork is NOT implement on pointClass"    testRaisesErrorSendWhenErrorInLookup    "(self selector: #testRaisesErrorSendWhenErrorInLookup) run"       self should: [ pointClass send: #zork withArguments: { aPoint } ] raise: Error.    "Open a Transcript to see the message trace" Le 19/11/15 13:50, Edouard Delbar a écrit : Hello everyone, I'm new on this mailing list, this is my first mail :-) I'm a student from University of Lille (France). I'm studying this tutorial (I'm using Pharo 4 but it seems not to be a problem): http://sdmeta.gforge.inria.fr/Teaching/ObjVLisp/ObjV.pillar.pdf. I'm working with the "ObjVLispSkeleton-StephaneDucasse.1" image loaded from this repository: MCSmalltalkhubRepository owner: 'StephaneDucasse' project: 'ObjVLispSkeleton' user: '' password: '' I'm stuck at "Method Lookup" p11. First, it seems that unit tests "testNilWhenErrorInLookup" and "testRaisesErrorSendWhenErrorInLookup" are not provided, thus I'm not sure that I'm working with the right image (everything was fine until p11 though). Then, the "lookup: selector" is not provided neither. While there is another method named "lookup: selector from: anObjObject", I can't figure out what I'm supposed to do with the second parameter. Ok I checked in the other method is old the new one should be lookup: selector    "look for the method named <selector> starting in the receiver.    The lookup is done for a message sent to <anObjObject>. self is an objClass"    Here is what I would do: lookup: selector "look for the method named <selector> starting in the receiver. The lookup is done for a message sent to <anObjObject>. self is an objClass" ^ self objMethodDict at: selector ifAbsent: [ self objSuperclassId ifNotNil: [ self objSuperclass lookup: selector ] ] Could someone tell me if this implementation is correct? If it's correct, what do you think the second parameter is for? Moreover, do you think I'm working with the right image? Thanks. - Edouard