Nitel Araştırmalarda Duygu Analizi (Sentiment Analysis) Üzerine Bir Vaka Çalışması-I

Genel olarak pozitif, negatif  ve nötr dilin ölçümü anlamına gelen duygu analizi fikir madenciliği (opinion mining) olarak da anılır. Bu analiz ürünlerden, reklamlardan, lokasyonlardan, reklamlardan ve hatta rakiplerden ortaya çıkan müşteri düşüncelerini açığa çıkarır. Müşterilerin hoşlandığı veya hoşlanmadığı ürünlerin tespitinde bu analiz önemli rol oynayarak, ürün gamı ve ürünün kalitesi buna göre şekillenmektedir. Diğer bir deyişle, firmalar müşterilerin ne hissettiğini ve düşündüğünü bilmesi gerekir. Bunun yanısıra duygu analizi (sentiment analysis) kendisine bir çok farklı alanda uygulama alanı bulmaktadır. Bunların bir kaçı şöyledir;

  • Politika
  • Hukuk
  • Sosyoloji
  • Psikoloji
  • Edebiyat
  • Pazarlama

Duygu analizi çalışmalarında duygu sözlükleri adı verilen “lexicon” lardan yaygın bir şekilde yararlandığı görülmektedir. Analizde kullanılan metin NRC lexiconu açısından analiz edilmiştir. NRC lexiconu hesaplamalı dil bilimci Saif Mohammad tarafından geliştirilmiş olup bu leksikon sözlüğünde pozitif ve negatif duyguları (sentiments) içeren 8 his (emotion) bulunmaktadır. Bu hisler şöyledir;

  1. Anger
  2. Anticipation
  3. Disgust
  4. Fear
  5. Joy
  6. Sadness
  7. Surprise
  8. Trust

Yukarıdan bahsedilen NRC leksikon testi, metindeki cümleler baz alınarak pozitif ve negatif duygu grubunda yapıldıktan sonra bu duygu grubu içinde yer alan 6 his için de yapılarak grafik olarak aşağıda sunulacaktır.

NRC leksikon testi yapıldıktan sonra ayrıca cümle bazında polarite (polarity) testi de yapılarak pozitif ve negatif duygulardan hangisinin metne hakim olduğu ortaya konulacaktır.

Aşağıda üzerinde örnek uygulama yapılacak 142 cümleden oluşan metin, “https://www.gutenberg.org/files/57646/57646-0.txt” web adresli açık kaynak kütüphanesinden alınmıştır. Yararlanılan metin,  M. S. Wellby’in  “Through Unknown Tibet” adlı eserinin 18’inci bölümünden alınarak özgün bir örnek uygulama yapılmıştır.

"We were now reduced to twenty-eight animals, and we knew our muleteers
to be so careless and untrustworthy a lot, that we resolved that
henceforth one of us should always remain with them and the mules—never,
in fact, let them out of our sight. This would ensure the animals being
properly cared for, and would be a prevention against the muleteers
forming any scheme for desertion. We decided, too, to make very easy
marches. We continued to see snow mountains in all directions, and
somehow or other managed to steer our way amongst them, either east or
north-east, over valleys and plains or stony nullahs, but we were most
unfortunate as to finding good grass. It must have been too early in
the year, for in many places it was just beginning to sprout.
Owing to the heavy loss to our transport we could only march some four
or five miles the next day, which brought us to a big fresh-water lake,
completely frozen over, resembling a large white sheet. Here we resolved
to lighten our loads, and left on the ground a number of cartridges,
horse shoes, cooking utensils, clothes, candles, etc., besides giving
the mules and ponies a feast of forty pounds of flour made into bread.
Some old pistols, rather heavy ones, which we had brought with us as
presents for natives, we allowed the men to carry themselves, on the
condition that should we require them as presents we would buy them
back from them, otherwise they might retain them for ever. Every one,
too, carried a certain number of cartridges, the men doing so under the
proviso that we would lend them a rifle when game was close to camp.
To celebrate the occasion we christened this lake Lake Lighten. The
size of this frozen water was deceptive. Our direction took us over
a portion of it which we reckoned to be about a mile across, but in
reality this turned out to be six miles. On the other side we found good
grass, and in a snug corner a very tiny fresh-water lake, or what we
should call at home a duck-pond. Here were geese, antelope, and kyang,
so we were able to make a substantial addition to our larder, which
at that time was in the same state as Mother Hubbard's cupboard. This
spot, too, became famous in its way for two events. First, it was here
discovered that one of our carbines had been left behind the day before,
and the men were so unwilling that none would go back to fetch it. To
do more than they were obliged to do was quite against their grain.
Secondly, another mule had to be shot, for he was too weak to rise and
march. The next day another pony met the same fate, and we began to
think our ammunition was more useful for this purpose than for killing
game, which, as a rule, was scarce. Our march took us another six miles
over the ice, and on the way we narrowly escaped losing one of the best
mules, who dropped his hind legs in a crack; luckily, he was extricated
unhurt, but he might easily have broken a leg.
On the 13th of June we camped by another salt lake. From the top of a
pass we had been rewarded with a very fine view of it, for the water
under a cloudless sky was of a wonderfully bright blue, backed as it was
by massive snow mountains, but detestable when near for its uselessness.
As we marched along its banks, the heat was intense, the maximum
thermometer registering 105° in the sun, and although there was no fresh
water to be seen, we found some by digging, though not enough to satisfy
our mules, and on making our tea, its constituency was, to say the least
of it, thick; perhaps Esau's description of it was nearer the mark, for
he said it was like jam. On warm days like this we were always glad
to discard our heavy boots, and coats, while our little terrier Ruby
could only lie and pant for breath. Such heat in the Chang at a height
of between fifteen and sixteen thousand feet may seem to some people
incredible. Its effect upon our animals was most disastrous, sapping
their strength in no small degree, and on this account we decided in
future to make an earlier march.In this little nullah we found three stones which from the way they were placed showed that they had been used for a fireplace, but not at
any very recent date, more likely two or three years ago. This was the
first sign of mankind since leaving Lanak La, and had probably been made
by some nomads who had wandered in this direction. We here consumed
two more of our remaining three bags of bhoussa, thereby still more
lightening our loads.According to our intention, camp was astir at 3.30 A.M., and we were
well off before 5 o'clock, and even at that hour it was so warm that our
gloves were not even wanted. It was a grand morning, and as we faced
the glorious rising sun, we were blinded by its brilliancy and found
it most difficult at first to see precisely where we were going. After
passing into a fairly grassy valley, the home of the kyang, we descended
to a fresh-water lake. At the time when the caravan was approaching this
water, we were both some distance off, shooting and taking observations,
and blamed ourselves afterwards at having left the muleteers. These
men knew the animals had been short of water lately, yet took no step
to prevent the calamity which naturally occurred at the sight of a
clean fresh-water lake. They, poor brutes, forgetful of the loads on
their backs, with one accord made a simultaneous rush to satisfy their
thirst. The water, although only two or three feet deep, concealed a
treacherous bottom of several feet of soft mud and as they plunged in
further and deeper, a general collapse ensued, and the mules and ponies
lay in a heap unable to extricate themselves, with a good chance too
of being drowned. Nor did any of our baggage benefit by the soaking
it received. Each animal as he lay had to be unloaded separately, no
easy undertaking, and then pulled out of the mud on his side by head
and tail, by four or five men. Furthermore the weight of each load was
considerably increased by this disaster, and as the going along the edge
of the water was not of the best, there were more stragglers than ever
into our new camp, two of them not even getting in at all. Around the
lake were several antelope, while geese and Brahmini ducks were fairly
plentiful.There appeared to be no outlet, and from the nature of the soil for some
distance round the lake, we judged that its size varied in accordance
with the rainfall. From this lake two routes were open to us, one
running in a somewhat northerly direction through a good, grassy,
watered valley, which we should have liked to have taken; but as the
other route led almost due east, we took it, and perhaps made a wrong
decision, for we came to a dried-up country, with small salt lakes, and
had to dig deep in a dry river bed for water. The antelope we had slain
made its mark upon the men, for the quantities of meat they ate made
them lazy and late in making a start the next morning.
As we moved off at six o'clock, there was a light mist hanging over the
land, with no breath of wind to dissolve it, a pretty sure sign of a hot
day. We began ascending for some miles, and then dipped into a dry river
bed. This looked a likely place to find water again by digging, and as
fair grass grew around, we decided to halt. We had only marched seven
miles, yet there were stragglers, and four loads had to be abandoned.
This loss we could ill afford, so agreed to halt another day, when we
could send back some of our stoutest mules and recover the baggage.
We had no fear whatever of a stranger turning up during the night and
running off with some of the goods. As we intended remaining another day
at this spot, it was indispensable that we should contrive some means
for watering the animals properly. We found water flowing three or four
feet below the surface, but a single hole was very quickly emptied, and
then we had to wait until it had refilled, so that watering in this
kind of way would have taken half the day. Every one, therefore, was
set to work to dig water-holes. We carried with us a large waterproof
sheet, and having made a trench in the sand, in the shape of a trough,
we spread the sheet over it, and then filled it up from the various
holes. In this way the mules and ponies could come and drink as often
and as much as they liked, and they probably would have drunk more than
they did, had not the water been somewhat saltish, with certain purging
qualities. We also set about lessening the loads again, and many of the
articles which we had imagined before to be absolutely necessary were
here discarded. Two of our five little tents were abandoned, and we took
the opportunity of photographing our last entire camp. Other things,
too, were left, for our animals were dying at an alarming rate. Out of
our original thirty-nine only twenty-one remained, including the riding
pony of Shahzad Mir. Our own riding days had before this come to an end.
Yet we had only come 150 miles from Lanak La, but our hopes of coming
across nomads, from whom we might either purchase yak or exchange some
of our own worn-out mules, strengthened us in our determination not to
entertain for a moment the idea of turning back. The men, too, were
so confident that we should ere long fall in with nomads that they
became lavish with their rations. Instead of continuing the practice of
doling their allowance out to them every three or four days, they had
latterly been permitted to have the full run of it, after being made
well aware how long the rations should last if they never exceeded the
amount agreed upon. This plan was instituted because in spite of all
our endeavours to regulate the consumption of food, yet in the dead of
night they would undo and take out whatever extra they fancied, even
when the foolhardiness of such a procedure was carefully explained to
them. Nevertheless, we reaped one advantage from their avarice, namely,
that the loads grew lighter in a shorter time than they otherwise would
have done. One man, Mahomed Rahim, annoyed at being upbraided for his
laziness and sulky temperament, threatened to turn back. This we gave
him full permission to do, much to his astonishment, and on second
thoughts he withdrew his threat, and even our own persuasion would not
induce him to go. During our halt we were able to overhaul all the luggage. Some of it
had suffered from the immersion in the lake, notably the contents of our
dispatch box, for all our papers inside it had had a thorough soaking,
and each one had to be put under a stone to be dried again, and to save
it from being blown away by the strong wind. About half a mile from our camp was a solitary hill rising up between eight and nine hundred feet above the level of the camp. I climbed over the rocks to the summit of this to spy out the land, and see which would
be the most favourable route to take. South-east of us lay a fine range
of snow mountains, and I reckoned that if we could manage to steer just
north of these, there would be no more difficulty about water to annoy
us. All the ranges, large and small, seemed to run east and west, and
it struck me how much more difficult, for this reason, it would be to
traverse Tibet from north to south. Directly south of us, some sixty or
eighty miles off, was another magnificent snow range with enormous white
peaks. Some six or eight miles south-east was a dark blue salt lake,
with two other smaller ones nestling close to it, and in the nullah
immediately south of us grew grass which, for this country, was rich.
Far away to the north again loomed another mighty snow range. Our own
way eastwards, as far as I could make out, would take us past a small
lake, and then, skirting round some low hills, turned up a nullah half
left, where there seemed, through my glasses, to be good grass.
On account of the heat we delayed our march till early in the afternoon.
During a part of the morning we tested the skill of our muleteers in
rifle shooting. We thought that, should we come across nomads who showed
any signs of hostility, our men would have more confidence in their
arms, and perhaps would not show the white feather. None of them could
hit an empty bottle at forty yards, so the confidence in their aim
received rather a demoralising shock.
Two days after leaving this camp, we crossed over an easy pass of
some 17,000 feet high, and about the top of this found a small white
butterfly and a yellow flower, the first we had seen, and it was
satisfactory to think that our flower press had not been carried along
all this way for nothing, for it nearly shared the same fate as other
things thrown away. A few miles further on, we camped in a grassy
nullah, close by some heavy, craggy rocks.
Finding the morning again too hot for the mules to march, we shouldered
our rifles and set forth in search of game, and to try and find out the
lay of the country ahead. We had completely run out of meat and had no
wish to slay our single sheep, which for many days had marched along
with us, the sole survivor of our flock. He had now become inured to
hardships, was never fatigued, and was looked upon as our very last
reserve in case of starvation. Although we actually found no game, yet
we saw tracks of antelope, kyang, and one or two entire skeletons of
yak.
We were rewarded for our tramp in another way, when, from some high
ground, we saw below us a fresh-water lake with rich grass growing
around it, and we wondered why nomads did not go and live there if they
knew of the spot. We hurried back to camp with the good news, so as to
march to such a paradise as soon as possible, and halt there another
day, to give our animals the opportunity of thoroughly enjoying the
luxurious spot. Poor brutes, strive as hard as they might, there had
been more casualties amongst them and we were reduced to nineteen, less
than half our original number.
On arrival at this lake, we found the centre portion of it was frozen
over. By the edge of the water were a number of geese; but they might as
well have been living in another country altogether, for they would give
us no chance of shooting them, and we began to meditate the slaughter of
our pet sheep, when, coming over the crest of a grassy rise, we spotted
a herd of antelope. They were certainly timid, but, with a lucky longish
shot, Malcolm knocked one over, saving us from hunger and our dear old
sheep from an unmerited death. How often we looked at our living mutton
with hungry feelings, it is hard to say, and how often an antelope just
saved him from the slaughter-house would be equally hard to relate. We
admired him, too, for his pluck and endurance, for he had long outstayed
every other member of the flock. Our affection for him was great, and we
even meditated his triumphal entry into China, and he would undoubtedly
have accomplished it, had not an unforeseen mishap later on demanded his
flesh and blood. Poor beast, if he had only known how we admired him,
he would willingly have given us a dinner long ago.
It was a great treat for all to get good water clear and fresh, for
latterly the water we had been digging up had been mostly muddy and
saltish. We were blessed with a perfect day for repose, the mules and
ponies grazed along the edge of the lake, sometimes standing up to their
fetlocks in the still water, a day of thorough enjoyment to them. All
their swellings and sores too were doctored up and the shoeing looked
to. Considering what they had undergone, their backs were in a very
satisfactory state. Tents and clothes were mended and a general clear-up
was organised, so much so that about midday, we and Ruby were bathing
in the lake itself, and although the lake was partly frozen over with
ice, and we were living at a height of nearly 16,000 feet, the water
was quite enjoyable, and we could remain splashing about in it for half
an hour, and afterwards bask naked in the sun. So much pleasure did we
derive from this bath that we ordered all the men down for tubbing. They
went, certainly, but the amount of washing they executed would not have
been sufficient for some people.
A climate like this at such a height struck us as truly marvellous.
After seventeen degrees of frost by night, we found ourselves basking in
the open in a temperature of 106 degrees, showing a variation of ninety
degrees in the twenty-four hours. At 7 P.M. again, the thermometer
registered as much as forty-eight degrees Fahr. Our route, as far as we
could make out, lay over a large open plain with but scanty grass, and
far off we could see a hill standing out alone conspicuously, a useful
landmark for us to march on to. Without a distinct feature to make for,
the caravan would very often zigzag down a broad valley and perhaps
cover a mile or two more of ground than was necessary.
We were off before 5 o'clock, with a keen morning air in our faces,
but after a couple of hours the heat became so unbearable that we would
fain have halted. We had, however, to march ten miles before we could
find a spot at all suitable, where, too, we had to resort to digging
for water. Around here we shot sand-grouse, excellent food. Owing to
the impossibility of marching with the sun so powerful, we decided to
make two short marches each day, one of three hours in the very early
morning, and the second during the afternoon. The drawbacks to this
method were the uncertainty of finding grass and water twice in one day,
and the fatigue involved in doubling the work of collecting the animals
and loading and unloading them. But to march ten miles straight away in
one morning as we had just done would have been suicidal. We reckoned
that by making these two short marches, we should cover rather more
ground each day, about twelve miles.
Whilst resting the animals, that they might recover from the results of
the hot morning's march, we sent Esau on in front to spy out the land,
who brought back the favourable news that lakes and grass were ahead of
us, and no mountains to climb. It was bitterly cold as we moved off at
4.30, but no doubt a bracing morning for our animals, but as soon as
the sun rose, the heat again made itself unpleasant, and we were glad
to find a suitable camp before 8 o'clock. One of the mules, a big black
one, could only carry his load a few yards, and had to be shot. Although
at the end of the first march we had found a good halting place in a
clean gravel-bedded nullah, with running water from the snow mountains,
and fair grass, yet the second march ended by moonlight with no grass
at all, and two of the ponies were left behind. Our second attempt at
a double march failed.
During the early morning we hit off a rivulet, which, as we continued
to follow it, increased in volume, but on issuing from the nullah into
a large open plain, this rivulet became a river, some ten yards across,
and two feet deep, and wound away northwards. As our course took us due
east, we reluctantly had to leave it, with the hope of meeting it again
further on, and of finding its size still larger, so that we might be
able to map out its course for a considerable distance. For some time
afterwards we could see a silver streak in the distance, and beyond it
an enormous range of snow mountains.
As soon as we left the river and marched east, our route lay across a
sandy gravel plain, and our chances of ever finding water and grass
again seemed very small, when, fortunately, from one of the hills I
climbed, I noticed a hidden dip in the ground, with grass, and here, as
usual, water was found by digging. The number of our animals was still
decreasing, and the strength of the survivors was growing weaker and
weaker. We had to economise every cupful of grain, for that was the way
we always doled it out. There were six bags remaining, in all about 480
pounds, and we reckoned that each bag would last out for eight marching
days if we gave to each animal two cupfuls of grain _per diem._ There
were only sixteen survivors. One of the mules showed an obstinate and
mutinous frame of mind, for when loaded with his fair due, he absolutely
refused to march; as soon as we gave him a light load, he trotted along
gaily and felt no effects from the march. He was about the fattest
and strongest mule we had, thereby convincing us that his inability to
carry his proper amount of baggage was a mere sham, and in order that
he should not get the better of us, we gave his grain to others who did
his work, until he saw the folly of his obstinacy.
On viewing the country from a neighbouring hill, I found that if
we marched due east we should meet with obstacles in the shape of
innumerable steep nullahs of red, sandy soil, but that by marching
north-east we should travel over undulating grassy ground skirting round
a small range of hills. This latter route we decided upon, with the
hopes of marching due east again before very long. We also made up our
minds to try and find a good camp where we could halt for two days, so
that during that time we could send off men north and south, with food
to last them, in order to search for signs of people. Even if the men
were not successful in their object, still we reflected that the animals
would be gaining strength and a complete rest all the while.
At 3.45 A.M., 23rd June, Camp 36, we were drinking our cocoa with
chupatty in the open, without feeling any discomfort from the cold,
preparatory to marching. We required neither gloves nor coats, and we
almost imagined we were about to start for an early morning shoot in the
Indian plains. For the next two days we made successful double marches,
inasmuch as there were no transport disasters. As usual, we dug for
water, and found it brackish for our labours.
Towards the end of the second day, we came to a small nullah with
beautifully green grass, and two tiny pools of water almost fresh.
Imprinted on the moist sandy soil were marks of kyang, antelope, and
yak. Evidently we had hit upon a favourite drinking resort of game, and
accordingly pitched our tents just out of sight but close to the pools,
expecting to get as much food as we wanted, for it was no easy matter
to keep ourselves supplied in meat. Although we stopped here a day, the
only game that came for his drink was a cock sand-grouse, who suffered
the penalty of death for his intrusion, while just above the camp was
an old hen, who sat undisturbed upon her nest. We should have had to be
a good deal hungrier than we were before we could have found it in our
hearts to kill her."

R’da yapılan analiz sonucunda, her bir leksikonun cümle düzeyindeki toplamları aşağıda gösterilmiştir.

NRC leksikonundaki 6 hissin metindeki yüzdesel yoğunluğu ise aşağıda grafikte gösterilmiştir. Burada, 6 his içinde güven (trust) hissinin öne çıktığı göze çarpmaktadır.

NCR leksikonuna göre metinde cümle bazlı pozitif ve negatif his grubunun skalası aşağıdaki grafikte özetlenmiş olup, pozitif hislerin ağırlıkta olduğu görülmektedir.

NRC leksikon testi yapıldıktan sonra cümle bazlı olarak polarite testi de yapılmıştır. Zıtlık anlamına gelen polarite testinde elde edilen sonuçlar -1 ile +1 arasındaki skalada değerlendirilir. Yeşil olan skorlar pozitif hissi, kırmızı olanlar ise negatiflik hissini göstermektedir. Aşağıdaki linkten cümle bazlı polarite testine ulaşabilirsiniz.

Pdf dokümanını indirmek için buraya tıklayınız : POLARİTE TESTİ

Yapılan bu çalışmaların, özellikle keşifsel veri analizi (exploratory data analysis), metin madenciliği (text mining) ve nitel araştırma alanına önemli bir katkı sunacağı inancındayım.

Faydalı olması dileğiyle…

Kaynak

Saif Mohammad and Peter Turney. “Emotions Evoked by Common Words and Phrases: Using Mechanical Turk to Create an Emotion Lexicon.” In Proceedings of the NAACL-HLT 2010 Workshop on Computational Approaches to Analysis and Generation of Emotion in Text, June 2010, LA, California. See: http://saifmohammad.com/WebPages/lexicons.html

Christopher SG Khoo and Sathik Basha Johnkhan. (2017). Lexicon-based sentiment analysis: Comparative evaluation of six sentiment lexicons. Journal of Information Science, 44(4):491-
https://doi.org/10.1177/0165551517703514.

http://saifmohammad.com/WebPages/meetsaif.htm

http://www.saifmohammad.com/WebPages/NRC-Emotion-Lexicon.htm

https://www.lexalytics.com/technology/sentiment

https://sites.nd.edu/emorgan/2014/07/lexicons/

NRC-Canada-2014: Detecting Aspects and Sentiment in Customer Reviews, Svetlana Kiritchenko, Xiaodan Zhu, Colin Cherry, and Saif M. Mohammad. In Proceedings of the eighth international workshop on Semantic Evaluation Exercises (SemEval-2014), August 2014, Dublin, Ireland.

NRC-Canada-2014: Recent Improvements in Sentiment Analysis of Tweets, Xiaodan Zhu, Svetlana Kiritchenko, and Saif M. Mohammad. In Proceedings of the eighth international workshop on Semantic Evaluation Exercises (SemEval-2014), August 2014, Dublin, Ireland.

Proceeding COLING ’04 Proceedings of the 20th international conference on Computational Linguistics,  Determining the sentiment of opinions, Geneva, Switzerland — August 23 – 27, 2004. Article No. 1367

Marina Sokolova , Guy Lapalme, Verbs speak loud: verb categories in learning polarity and strength of opinions, Proceedings of the Canadian Society for computational studies of intelligence, 21st conference on Advances in artificial intelligence, p.320-331, May 28-30, 2008, Windsor, Canada

Not: Emeğe saygı adına, yapılan çalışmanın başka bir mecrada ya da ortamda paylaşılması halinde alındığı yer adının belirtilmesini rica ederim.

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